Editing Citation index (section)

{{Short description|Index of citations between publications}}
{{distinguish|Citation impact}}
[[File:Citation indexes.jpg|thumb|Citation index]]
{{Citation metrics}}

A '''citation index''' is a kind of [[bibliographic index]], an index of [[citation]]s between publications, allowing the user to easily establish which later documents cite which earlier documents.<ref>{{cite encyclopedia |last1=Gómez-Morales |first1=Yuri Jack |title=Citations and Scientific Indexing |encyclopedia=The Blackwell Encyclopedia of Sociology |date=2015 |doi=10.1002/9781405165518.wbeosc037.pub2 |isbn=9781405165518}}</ref> A form of citation index is first found in 12th-century Hebrew religious literature. Legal citation indexes are found in the 18th century and were made popular by [[citator]]s such as [[Shepard's Citations]] (1873). In 1961, [[Eugene Garfield]]'s [[Institute for Scientific Information]] (ISI) introduced the first citation index for papers published in [[academic journal]]s, first the ''[[Science Citation Index]]'' (SCI), and later the ''[[Social Sciences Citation Index]]'' (SSCI) and the ''[[Arts and Humanities Citation Index]]'' (AHCI). [[American Chemical Society]] converted its printed [[Chemical Abstract Service]] (established in 1907) into internet-accessible [[SciFinder]] in 2008. The first automated citation indexing <ref> Giles, C. Lee, Kurt D. Bollacker, and Steve Lawrence. "CiteSeer: An automatic citation indexing system." In Proceedings of the third ACM conference on Digital libraries, pp. 89-98. 1998.</ref> was done by [[CiteSeer]] in 1997 and was patented.<ref> SR Lawrence, KD Bollacker, CL Giles "Autonomous citation indexing and literature browsing using citation context; US Patent 6,738,780, 2004.</ref> Other sources for such data include [[Google Scholar]], [[Microsoft Academic]], Elsevier's [[Scopus]], and the [[National Institutes of Health]]'s ''[https://icite.od.nih.gov iCite]''.<ref name="nih2019">{{cite journal |last1=Hutchins |first1=BI |last2=Baker |first2=KL |last3=Davis |first3=MT |last4=Diwersy |first4=MA |last5=Haque |first5=E |last6=Harriman |first6=RM |last7=Hoppe |first7=TA |last8=Leicht |first8=SA |last9=Meyer |first9=P |last10=Santangelo |first10=GM |title=The NIH Open Citation Collection: A public access, broad coverage resource. |journal=PLOS Biology |date=October 2019 |volume=17 |issue=10 |pages=e3000385 |doi=10.1371/journal.pbio.3000385 |pmid=31600197|pmc=6786512 |doi-access=free }}</ref>