Citation analysis is the examination of the frequency, patterns, and graphs of citations in articles and books. It uses citations in scholarly works to establish links to other works or other researchers. Citation analysis is one of the most widely used methods of bibliometrics. For example, bibliographic coupling and co-citation are association measures based on citation analysis (shared citations or shared references).
Automated citation indexing has changed the nature of citation analysis research, allowing millions of citations to be analyzed for large-scale patterns and knowledge discovery. The first example of automated citation indexing was CiteSeer, later to be followed by Google Scholar.
Today citation analysis tools are easily available to compute various impact measures for scholars based on data from citation indices. These have various applications, from the identification of expert referees to review papers and grant proposals, to providing transparent data in support of academic merit review, tenure, and promotion decisions.
Citation Analysis for legal documents 
Citation analysis for legal documents is an approach to facilitate the understanding and analysis of inter-related regulatory compliance documents by exploration of the citations that connect provisions to other provisions within the same document or between different documents. Citation analysis uses a citation graph extracted from a regulatory document, which could supplement E-discovery - a process that leverages on technological innovations in big data analytics.
Issues raised by electronic publishing 
Due to the unprecedented growth of electronic resource (e-resource) availability, one of the questions currently being explored is, "how often are e-resources being cited in my field?" For instance, there are claims that on-line access to computer science literature leads to higher citation rates, however, humanities articles may suffer if not in print.
See also 
Methods of citation analysis for document similarity computation 
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- Examples include subscription-based tools based on proprietary data, such as Web of Science and Scopus, and free tools based on open data, such as Scholarometer
- Hoang, D.; Kaur, J. and Menczer, F. (2010), "Crowdsourcing Scholarly Data", Proceedings of the WebSci10: Extending the Frontiers of Society On-Line, April 26-27th, 2010, Raleigh, NC: US
- Mohammad Hamdaqa and A. Hamou-Lhadj, "Citation Analysis: An Approach for Facilitating the Understanding and the Analysis of Regulatory Compliance Documents", In Proc. of the 6th International Conference on Information Technology, Las Vegas, USA
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- Zhao, Lisa. "How Librarian Used E-Resources--An Analysis of Citations in CCQ." Cataloging & Classification Quarterly 42(1) (2006): 117-131.
- Lawrence, Steve. Free online availability substantially increases a paper's impact. Nature volume 411 (number 6837) (2001): 521. Also online at http://citeseer.ist.psu.edu/online-nature01/