Wikipedia:Citing sources

WP:REF redirects here. You may be looking for Wikipedia:Reference Desk.

A citation is a line of text that uniquely identifies a source. For example:

Ritter, Ron. The Oxford Style Manual. Oxford University Press, 2002, p. 1.

When and why to cite sources: The policy on sourcing is Verifiability. This requires inline citations for any material challenged or likely to be challenged, and for all quotations. The policy is strictly applied to all material in the mainspace—articles, lists, captions, and sections of articles—without exception. In the event of a contradiction between this page and the policy, the policy takes priority, and this page should be updated to reflect it. Sourcing also applies to images: when an image is uploaded, the uploader must say where the image came from and indicate its copyright status.

How to write citations: Each article should use the same citation method throughout. If an article already has citations, adopt the method in use or seek consensus on the talk page before changing it. While you should try to write citations correctly, what matters is that you provide enough information to identify the source. Others will improve the formatting if needed.

Use of terms

• The word "source" has three meanings on Wikipedia: the piece of work itself (e.g. A Theory of Justice), the creator of the work (e.g. John Rawls), and the publisher of the work (e.g. Harvard University Press). How reliable a source is can depend on just one of these factors, or on all three.
• A "citation" is a line of text that identifies a source; for example, Rawls, John. A Theory of Justice. Harvard University Press, 1971, p. 1.
• The word "reference" may refer to the citation or the source.
• The terms "footnote" and "note" are used interchangeably; the term "endnote" is not used on Wikipedia.
• The terms "Further reading" or "External links" are used as section headings for books, articles, and websites related to the topic that have not been used as sources.

How to format and place citations

Inline citations

An inline citation is a line of text identifying a source that is added close to the material it supports, offering text-source integrity. If a word or phrase is particularly contentious, an inline citation may be added next to it within a sentence, but adding the citation to the end of the sentence or paragraph is usually sufficient, so long as it is clear which source supports which part of the text. Editors are free to use any method for inline citations; no method is recommended over any other. Two common styles of inline citation used on Wikipedia are clickable footnotes (<ref> tags) and parenthetical references.

A quick how-to

Most editors add inline citations inside footnotes; see below for more details. One easy way to write them is to add this to the end of the relevant phrase, sentence, or paragraph:

• <ref>Rawls, John. ''A Theory of Justice''. Harvard University Press, 1971, p. 1.</ref>
• <ref>Sanger, David E. [http://www.nytimes.com/2010/09/24/world/24prexy.html?_r=1&hp "With Warning, Obama Presses China on Currency"], ''The New York Times'', September 23, 2010, accessed October 31, 2010.</ref>

Then add this to the end of the article:

==Notes==

{{Reflist}}

Footnotes

Further information: Wikipedia:Footnotes and Help:Footnotes

Most Wikipedia articles place their citations in footnotes. These appear as clickable numbers within the text, which link to a numbered list of full citations at the end of the article. The citations will appear at the end of the article if you type {{Reflist}}. This will generate the list of footnotes. This is usually called the References or Notes section.

For a citation to appear in a footnote, it must be enclosed within "ref" tags. You can add these by typing <ref> at the front of the citation and </ref> at the end. Alternatively use the list of "markup" in the edit box, which includes <ref></ref>. You can also use the name attribute by using <ref name=name>details of the citation</ref>. Thereafter, the same footnote may be used multiple times by adding <ref name=name/>. If the name contains an embedded blank, you must add straight quotation marks (<ref name="name more"/>) or replace the unacceptable blank character with an acceptable character such as an underscore or a hyphen (e.g., <ref name=name_more/> or <ref name=name-more/>), thus eliminating the need for quotation marks.

This is how it looks in the edit box:

The sun is pretty big,<ref>Miller, Edward. ''The Sun''. Academic Press, 2005, p. 1.</ref> but the moon is not so big.<ref>Brown, Rebecca. "Size of the Moon," ''Scientific American'', 51(78):46.</ref> The sun is also quite hot.<ref>Smith, John. ''The Sun's Heat''. Academic Press, 2005, p. 2.</ref>

==Notes==
{{Reflist}}

This is how it looks in the article:

The sun is pretty big, but the moon is not so big. The sun is also quite hot.

Notes

---

Shortened footnotes

Many articles use short citations in footnotes, giving the author, year, and page number, such as <ref>Smith 2010, p. 1.</ref> As before, the list of footnotes is automatically generated in a "Notes" or "Footnotes" section. A full citation is then added in a "References" section. Short citations can be written manually, or by using the {{sfn}} or {{harvnb}} templates, though note that templates should not be added without consensus to an article that already uses a consistent referencing style. If using templates, the short citation and the full citation may be linked so that the reader may click on the short note to highlight the full citation (see wikilinks to full references). For examples, see here.

This is how short citations look in the edit box:

The sun is pretty big,<ref>Miller 2005, p. 1.</ref> but the moon is not so big.<ref>Brown 2006, p. 2.</ref> The sun is also quite hot.<ref>Miller 2005, p. 3.</ref>

== Notes ==
{{Reflist}}

== References ==
*Brown, Rebecca (2006). "Size of the Moon," ''Scientific American'', 51(78).
*Miller, Edward (2005). ''The Sun''. Academic Press.

This is how they look in the article:

The sun is pretty big, but the moon is not so big. The sun is also quite hot.

Notes

---

References

---

• Brown, Rebecca (2006). "Size of the Moon", Scientific American, 51(78).
• Miller, Edward (2005). The Sun. Academic Press.

Shortened notes using titles rather than publication dates would look like this in the article:

Notes

---

List-defined references

Further information: Help:Footnotes § List-defined references, and WP:LDR

As of September 2009, the Cite.php extension was modified to support list-defined references. These can be implemented with the |refs= parameter to the {{Reflist}} template, or by using a pair of HTML tags (<references> and </references>) in place of the <references /> tag. These reduce clutter within articles, by putting all the citation details in the section at the end where the footnotes are displayed. Defined references must be used within the body; unused references will show an error message. Non-list-defined references (ordinary footnote references enclosed with <ref> and </ref> tags) will display as normal along with list-defined ones. As with other citation formats, list-defined references should not be added to articles that already have a stable referencing system, unless there is consensus to do so. When in doubt, use the referencing system added by the first major contributor to use a consistent style.

This is how it looks in the edit box::

The Sun is pretty big,<ref name="Miller2005p23" /> but the Moon is not so big.<ref name="Brown2006" /> The Sun is also quite hot.<ref name="Miller2005p34" />

==Notes==
{{Reflist|refs=
<ref name="Miller2005p23">Miller, Edward.''The Sun''. Academic Press, 2005, p. 23.</ref>
<ref name="Miller2005p34">Miller, Edward.''The Sun''. Academic Press, 2005, p. 34.</ref>
<ref name="Brown2006">Brown, Rebecca. "Size of the Moon," ''Scientific American,'' 51(78):46</ref>
}}

This is how it looks in the article:

The Sun is pretty big, but the Moon is not so big. The Sun is also quite hot.

Notes

---

Parenthetical referencing

Further information: Wikipedia:Parenthetical referencing

In parenthetical referencing, a short citation, such as (Smith 2010, p. 1), is added in parentheses (round brackets) just after the point it is supporting. Several forms of parenthetical referencing are used in Wikipedia, including author-date referencing (APA style, Harvard style, or Chicago style), and author-title or author-page referencing (MLA style or Chicago style). The full citation (Smith, John. Name of Book. Cambridge University Press, 2010) is then added in alphabetical order, according to the authors' surnames, at the end of the article in a "References" section. The inline and full citation may be linked using a template (see linking inline and full citations); as with other citation templates, these should not be added to articles without consensus.

This is how it looks in the edit box:

The Sun is pretty big (Miller 2005, p. 1), but the Moon is not so big (Brown 2006, p. 2). The Sun is also quite hot (Miller 2005, p. 3).
== References ==
*Brown, R (2006). "Size of the Moon", ''Scientific American'', 51(78).
*Miller, E (2005). ''The Sun'', Academic Press.

This is how it looks in the article:

The Sun is pretty big (Miller 2005, p. 1), but the Moon is not so big (Brown 2006, p. 2). The Sun is also quite hot (Miller 2005, p. 3).

References

---

• Brown, R (2006). "Size of the Moon", Scientific American, 51(78).
• Miller, E (2005). The Sun, Academic Press.

Text-source integrity

When using inline citations, it is important to maintain text-source integrity. The point of an inline citation is to allow readers and other editors to check that the material is sourced; that point is lost if the citation is not clearly placed. The distance between material and its source is a matter of editorial judgment, but adding text without placing its source clearly can lead to allegations of original research, violations of the sourcing policy, and even plagiarism. Editors should exercise caution when rearranging or inserting material to ensure that text-source relationships are maintained.

The following inline citation, for example, is not helpful, because the reader does not know whether each source supports the material; each source supports part of it; or just one source supports it with the others added as further reading:

N Delia Smith is the UK's best-selling cookery writer.

Where you are using multiple sources for one sentence, consider bundling citations at the end of the sentence or paragraph with an explanation in the footnote regarding which source supports which point; see below for how to do that.

Bundling citations

Further information: Wikipedia:Citation overkill

You can combine or "bundle" citations between one set of ref tags at the end of a sentence or paragraph, along with an explanation in the footnote for which source supports which part of the text. Citation bundling can be done with long or short footnotes, with or without citation templates. It has multiple benefits:

• it helps readers and other editors see at a glance which source supports which point, maintaining text-source integrity;
• it avoids the visual clutter of multiple clickable footnotes inside a sentence or paragraph;
• it avoids the confusion of having multiple sources listed separately after sentences, with no indication of which source to check for each part of the text, such as this.
• it makes it less likely that inline citations will be moved inadvertently when text is re-arranged, because the footnote states clearly which source supports which point.

A simple example of citation bundling:

The sun is pretty big, but the moon is not so big. The sun is also quite hot.

Notes

---

In-text attribution

In-text attribution is the attribution inside a sentence of material to its source, in addition to an inline citation in a footnote after the sentence. For example:

Y John Rawls argues that, to reach a fair decision, parties must consider the matter as if behind a veil of ignorance.

An inline citation should follow the attribution, either after the phrase, sentence, or paragraph in question. In-text attribution should be used with direct speech (a source's words between quotation marks); indirect speech (a source's words without quotation marks); and close paraphrasing. It can also be used, optionally, when summarizing a source's position in your own words. Using in-text attribution avoids inadvertent plagiarism, and also helps to orient the reader as to where the position is coming from. It is therefore often a helpful thing to add, though caution is required to make sure the attribution does not lead to an inadvertent neutrality violation. For example:

N Professor John Smith argues that human-caused increases in atmospheric carbon dioxide have led to global warming, though Professor Susan Jones maintains that Smith has misread the data.

In some contexts this sentence could mislead, because it implies parity between the sources, and that Smith may be the only person holding his position, whereas his view is held by the majority of climatologists. This kind of issue can be fixed by writing "Professor John Smith, for example, argues..." or "Professor John Smith, following the majority view, argues..." Neutrality issues apart, there are other ways in-text attribution can mislead. The sentence below suggests that The New York Times has alone made this important discovery:

N According to The New York Times, the sun will set in the west this evening.

Simple facts such as this can have inline citations to reliable sources as an aid to the reader, but normally the text itself is best left as a plain statement without in-text attribution:

YBy mass, oxygen is the third most abundant element in the universe after hydrogen and helium.

Dealing with unsourced material

If an article is unreferenced you can tag it with the template {{Unreferenced}}, so long as it is not nonsensical or a biography of a living person, in which case request admin assistance.

• If a claim is doubtful but not harmful, use the {{fact}} tag, which will add "citation needed," but remember to go back and remove the claim if no source is produced within a reasonable time.
• If a claim is doubtful and harmful, remove it from the article. You may want to move it to the talk page and ask for a source, unless it is very harmful or absurd, in which case it should not be posted to the talk page either. Use your common sense.
• All unsourced and poorly sourced contentious material about living persons must be removed from articles and talk pages immediately. See Wikipedia:Biographies of living persons and Wikipedia:Libel.

Some general advice

When and why to cite sources

• Cite sources when

• adding or restoring material that is challenged or likely to be challenged,
• quoting someone, with or without quotation marks, or closely paraphasing a source,
• summarizing source material in your own words, in order to give credit to the source of your ideas,
• uploading an image.

• Citing sources

• ensures that content can be checked by any reader or editor, which improves the credibility of Wikipedia,
• shows that your edit is not original research, plagiarism, or a copyright violation,
• ensures that material about living persons complies with the biography of living persons policy,
• helps readers find additional information.

Say where you read it

Don't cite a source unless you've seen it for yourself. Where you want to cite John Smith, but you've only read Paul Jones who cites Smith, write it like this (this formatting is just an example; there are several ways this can be written):

Smith, John. Name of Book I Haven't Seen, Cambridge University Press, 2009, p. 1, cited in Paul Jones (ed.). Name of Encyclopedia I Have Seen. Oxford University Press, 2010, p. 2.

For a source available in hardcopy, microform, and/or online, omit, in most cases, which one you read. While it is useful to cite author, title, edition (1st, 2d, etc.), and similar information, it generally is not important to cite a database such as ProQuest, EbscoHost, or JStor (see the list of academic databases and search engines) or to link to such a database requiring a subscription or a third party's login. The basic bibliographic information you provide should be enough to search for the source in any of these databases that have the source. Don't add a URL that has a part of a password embedded in the URL. However, you should provide the DOI, ISBN, or another uniform identifier, if available. If the publisher offers a link to the source or its abstract that does not require a payment or a third party's login for access, you should provide the URL for that link. And if the source exists only online, give the link even if access is restricted.

Non-English sources

Main page: Wikipedia:Verifiability § Non-English sources

Because this is the English Wikipedia, English-language sources should be used in preference to non-English language sources of equal caliber and content, though the latter are allowed where appropriate. When quoting a source in a different language, please provide both the original-language quotation and an English translation, in the text, in a footnote, or on the talk page as appropriate.

Convenience links

Main page: Wikipedia:Copyrights § Linking to copyrighted works

A convenience link is a link to a copy of your source on a webpage provided by someone other than the original publisher or author. For example, a copy of a newspaper article no longer available on the newspaper's website may be hosted elsewhere. When offering convenience links, it is important to be reasonably certain that the convenience copy is a true copy of the original, without any changes or inappropriate commentary, and that it does not infringe the original publisher's copyright. Accuracy can be assumed when the hosting website appears reliable. Where several sites host a copy of the material, the site selected as the convenience link should be the one whose general content appears most in line with Wikipedia:Neutral point of view and Wikipedia:Verifiability.

Multimedia

Multimedia material should be referenced just like article text. Citations for a media file should appear on its file page. Image captions should be referenced as appropriate just like any other part of the article. If an infobox or table contains text that needs citing, but the box or table cannot incorporate an inline citation, the citation should appear in a caption or other text that discusses the material. A citation is not needed for descriptions such as alt text that are verifiable directly from the image itself. Material that identifies a source (e.g., the caption "Belshazzar's Feast (1635)" for File:Rembrandt-Belsazar.jpg) is considered attribution and normally does not need further citation.

Avoid scrolling lists

Scrolling lists, or lists of citations appearing within a scroll box, should never be used because of issues with readability, accessibility, printing, and site mirroring. Additionally, it cannot be guaranteed that such lists will display properly in all web browsers. See this July 2007 discussion for more detail.

General reference

A general reference is a citation to a reliable source that supports content, but is not displayed as an inline citation. General references are usually listed at the end of the article in a References section. They may be found in underdeveloped articles, especially when all article content is supported by a single source. The disadvantage of using general references is that text-source integrity is lost, unless the article is very short. The sourcing policy, Verifiability, requires inline citations for all quotations, and for anything challenged or likely to be challenged.

A general reference looks like this in the edit box:

The Sun is pretty big, but the Moon is not so big. The Sun is also quite hot.

== References ==
*Brown, R (2006). "Size of the Moon", ''Scientific American'', 51(78).
*Miller, E (2005). ''The Sun'', Academic Press.

This is how it looks in the article:

The Sun is pretty big, but the Moon is not so big. The Sun is also quite hot.

References

---

• Brown, R (2006). "Size of the Moon", Scientific American, 51(78).
• Miller, E (2005). The Sun, Academic Press.

Embedded links

Further information: Wikipedia:Embedded citations

Embedded links to external websites should not be used as a form of inline citation, because they are highly susceptible to linkrot. Wikipedia allowed this in its early years—for example by adding a link after a sentence, like this [http://media.guardian.co.uk/site/story/0,14173,1601858,00.html], which looks like this. [1] This is no longer recommended. Raw links are not recommended in lieu of properly written out citations, even if placed between ref tags, like this <ref>[http://media.guardian.co.uk/site/story/0,14173,1601858,00.html]</ref>.

Embedded links should never be used to place external links in the body of an article, like this: "Apple, Inc. announced their latest product..."

What information to include

Citation styles and consistency

See also: Citation, APA style, MLA style, The Chicago Manual of Style, Author-date referencing, Vancouver system, Bluebook, and Wikipedia:Citing sources/example style

There are a number of citation styles. See here for some examples. They all include the same information, but vary in punctuation and the order of the author's name, publication date, title, and page numbers. Citations in Wikipedia articles should be internally consistent. You should follow the style already established in an article if it has one; where there is disagreement, the style used by the first editor to use one should be respected.

Examples

Books

Citations for books typically include:

• name of the author(s)
• title of the book in italics
• volume when appropriate
• city of publication is optional
• name of the publisher
• year of publication
• chapter or page number(s) where appropriate
• ISBN is optional

Citations for individually authored chapters in books typically include:

• name of author
• the title of the chapter
• name of the book's editor
• name of book and other details as above
• the chapter number or page numbers for the chapter are optional

Journal articles

Citations for journal articles typically include:

• name of the author(s)
• year and sometimes month of publication
• title of the article within quotation marks
• name of the journal in italics
• volume number, issue number, and page numbers (article numbers in some electronic journals)

Newspaper articles

Citations for newspaper articles typically include:

• name of the newspaper in italics
• date of publication
• byline (author's name), if any
• title of the article within quotation marks
• city of publication, if not included in name of newspaper
• page number(s) are optional

Webpages

Citations for World Wide Web pages typically include:

• name of the author(s)
• title of the article within quotation marks
• name of the website
• date of publication
• page number(s) (if applicable)
• the date you retrieved it (required if the publication date is unknown)

Identifying parts of a source

When citing lengthy sources, you should identify which part of a source is being cited. For example, in the case of a book, specify the page number(s). Page numbers are not required for a reference to the book as a whole. When you specify a page number, it is helpful to specify the version (date and edition for books) of the source because the layout, pagination, length, etc. can change between editions.

Links and ID numbers

A citation ideally includes a link or ID number to help editors locate the source. If you have a URL (webpage) link, you can add it to the title part of the citation, so that when you add the citation to Wikipedia the URL becomes hidden and the title becomes clickable. To do this, enclose the URL and the title in square brackets—the URL first, then a space, then the title. For example:

Carr A, Ory D (2006). [http://dx.doi.org/10.1371/journal.pmed.0030496 Does HIV cause cardiovascular disease?] ''PLoS Medicine'', 3(11):e496.

For web-only sources with no publication date you should include a "Retrieved" date instead, in case the webpage changes in the future. For example: Retrieved 2008-07-15.

You can also add an ID number to the end of a citation. The ID number might be an ISBN for a book, a DOI (Digital Object Identifier) for an article, or any of several ID numbers that are specific to particular article databases, such as a PMID number for articles on PubMed. It may be possible to format these so that they are automatically activated and become clickable when added to Wikipedia, for example by typing ISBN (or PMID) following by a space followed by the ID number.

If your source is not available online, it should be available in reputable libraries, archives, or collections. If a citation without an external link is challenged as unavailable, any of the following is sufficient to show the material to be reasonably available (though not necessarily reliable): providing an ISBN or OCLC number; linking to an established Wikipedia article about the source (the work, its author, or its publisher); or directly quoting the material on the talk page, briefly and in context.

Citation templates and tools

Further information: Wikipedia:Citation templates and Wikipedia:Citation tools

For a comparison of citations using templates with citations written freehand, see Wikipedia:Citing sources/Example edits for different methods.

Citation templates are used to format citations in a consistent way. The use of citation templates is neither encouraged nor discouraged. Templates may be used or removed at the discretion of individual editors, subject to agreement with other editors on the article. Because templates can be contentious, editors should not change an article with a distinctive citation format to another without gaining consensus. Where no agreement can be reached, defer to the style used by the first major contributor.

There are several webpages/tools that can help quickly produce a citation in a standard template format. You may only need one piece of information and they can fill in the rest of the details. The resulting citation will be enclosed in "cite" tags, and it will be formatted in a particular way depending on which kind of template is being used. You can then copy all the text from there. It may still require additional tags before you can add it to a Wikipedia article.

Metadata

Citations may be accompanied by metadata, though it is not mandatory. Most citation templates on Wikipedia use the COinS microformat. Metadata such as this allow browser plugins and other automated software to make citation data accessible to the user, for instance by providing links to their library's online copies of the cited works. In articles that format citations manually, metadata may be added manually in a span, according to the COinS specification; or the templates Template:Citation metadata or Template:COinS can be used.

Citation processing tools

• Template:Citation/core – a core template used by other citation templates
• User:Citation bot (formerly DOI bot) – a bot that automatically fixes common errors in individual citations, and adds missing fields
• User:CitationTool – a tool for finding article-level citation errors and fixing them. Not currently functional.

Programming tools

• Wikicite is a free program that helps editors to create citations for their Wikipedia contributions using citation templates. It is written in Visual Basic .NET, making it suitable only for users with the .NET Framework installed on Windows, or, for other platforms, the Mono alternative framework. Wikicite and its source code is freely available; see the developer's page for further details.
  • Wikicite+ is a program based on the original Wikicite source code. It features extra validation, bug fixes, additional cite templates (such as cite episode) as well as tools for stub sorting and more. It is also available for free under the Apache License 2.0 and is open source.
• User:Richiez has tools to automatically handle citations for a whole article at a time. Converts occurrences of {{pmid XXXX}} or {{isbn XXXX}} to properly formatted footnote or Harvard-style references. Written in ruby and requires a working installation with basic libraries.
• pubmed2wiki.xsl an XSL stylesheet transforming the XML output of PubMed to Wikipedia refs.
• RefTag by Apoc2400 creates a prefilled {{cite book}} template with various options from a Google Books URL. The page provides a bookmarklet for single-click transfer.
• wikiciter web interface, does google books, pdf files, beta.

Citation export tools

You can insert a link beside each citation in Wikipedia, allowing you to export the citation to a reference manager, such as EndNote. Just copy this code:

importScript("User:Smith609/endnote.js");

to the end of Special:MyPage/monobook.js. Then, save the page and bypass your browser's cache.

Preventing and repairing dead links

See also: Wikipedia:Link rot

To help prevent dead links, persistent identifiers are available for some sources. Some journal articles have a digital object identifier (DOI); some online newspapers and blogs, and also Wikipedia, have permalinks that are stable. When permanent links aren't available, consider archiving the referenced document when writing the article; on-demand web archiving services such as WebCite (http://www.webcitation.org) are fairly easy to use (see pre-emptive archiving). Dead links should be repaired or replaced if possible.

• First, check the link to confirm that it is dead. The site may have been temporarily down or have changed its linking structure.
• The Internet Archive (http://www.archive.org/) has billions of archived webpages. There may be a delay of six months before a link shows up there. See Wikipedia:Using the Wayback Machine.
• UK Government Web Archive (http://www.nationalarchives.gov.uk/webarchive/), a project of The National Archives, preserves 1500 UK central government websites captured by the European Archive Foundation.
• Remove the dead link and keep the citation without a link if the material exists offline; for example a journal or newspaper article.
• If the source material does not exist offline, and if there is no archived version of the webpage, then the citation should be removed and the material it supports should be regarded as unsourced.

See also

How to cite

• Wikipedia:Verification methods – listing examples of the most common ways that citations are used in Wikipedia articles.
• Wikipedia:Citing sources/example style – listing examples of full citations using APA and Harvard referencing techniques.
• Wikipedia:Citing sources/Example edits for different methods – showing comparative edit mode representations for different citation methods and techniques.
• Wikipedia:Citing sources/Further considerations – information of additional interest.
• Wikipedia:Citation templates – a full listing of various styles for citing all sorts of materials.
• Wikipedia:External links – for information about the External links appendix
• Wikipedia:Improving referencing efforts
• Wikipedia:Inline citation
• Wikipedia:Layout#Further reading – for information about the Further reading appendix
• Wikipedia:List of sources
• Wikipedia:Referencing for beginners – a simple practical guide to getting started.
• Wikipedia:Scientific citation guidelines – guidelines for dealing with scientific and mathematical articles.

Citation problems

• Template:Citations missing – template to add where citations are needed
• Wikipedia:A suggested improvement 0001
• Wikipedia:Linkrot – guide to preventing link rot
• Wikipedia:Citation needed – explanation of citation needed template
• Wikipedia:Copyright problems – in case of text that has been copied verbatim inappropriately.
• Wikipedia:WikiProject Citation cleanup – a group of people devoted to cleaning citations
• Wikipedia:Bombardment – an essay regarding the overuse of citations
• Wikipedia:Citation overkill – why too many citations on one fact can be a bad thing
• Wikipedia:Video links – an essay discussing the use of citations linking to YouTube and other user-submitted video sites
• Wikipedia:You don't need to cite that the sky is blue

Other

• Comparison of reference management software – side-by-side comparison of various Reference management software

References

• Concordia Libraries (Concordia University). Citation and Style Guides.
• Ritter, R. (2002). The Oxford Style Manual. Oxford University Press. ISBN 0198605641
• The Writers' Workshop, Center for Writing Studies. "Citation Styles Handbook: APA", University of Illinois.
• The Writers' Workshop, Center for Writing Studies. "Citation Styles Handbook: MLA", University of Illinois.
• University of Chicago Press. (2003). The Chicago Manual of Style, 15th edition. ISBN 0-226-10403-6

Further reading

• A writer's practical guide to MLA documentation
• AMA Citation Style
• Chicago/Turabian Documentation
• Template:PDFlink
• Guide to Citation Style Guides
• Uniform Requirements for Manuscripts Submitted to Biomedical Journals
• American Chemical Society reference style guidelines
• Citation Machine