Citation searching, also known as cited reference searching, is a search for books and articles that cite a previously published resource.
Searching for Cited References
Citation indexes track references that authors put in the bibliographies of published papers. They provide a way to search for and analyze the literature in a way not possible through simple keyword/topical searching. It also enables users to gather data on the "impact" of journals, as well as assessing particular areas of research activity and publication. This field is called bibliometrics.
Citation indexes can find references that cite earlier references; how many times my reference has been cited; determine what are the best journals in my field; and verify obscure references.
Citation searching is only available on a small number of databases.
The importance and "impact" of scholarly research articles are often measured by
For further information, see Citation Searching and Bibliometric Measures from C&RL News (pdf)