"A bibliographer is a person who describes and lists books and other publications, with particular attention to such characteristics as authorship, publication date, edition, typography, etc. The result of this endeavor is a bibliography. A person who limits such efforts to a specific field or discipline is a subject bibliographer." 
A bibliographer, in the technical meaning of the word, is anyone who writes about books. But the accepted meaning since at least the 18th century is a person who attempts a comprehensive account—sometimes just a list, sometimes a fuller reckoning—of the books written on a particular subject. In the present, bibliography is no longer a career, generally speaking; bibliographies tend to be written on highly specific subjects and by specialists in the field. For the bibliographers in Wikipedia Category:Bibliographers, assembling and categorizing books was either a major professional pursuit or a lifelong avocation.
There are more than a hundred bibliographers mentioned in Wikipedia. Search via Category:Bibliographers.
- Reitz, Joan M. (2010) Online Dictionary for Library and Information Science
- "MLA Field Bibliographers". Mla.org. Retrieved 2013-10-08.