A citation index is a kind of bibliographic index, an index of citations between publications, allowing the user to easily establish which later documents cite which earlier documents. 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 citators such as Shepard's Citations (1873). In 1960, Eugene Garfield's Institute for Scientific Information (ISI) introduced the first citation index for papers published in academic journals, first the Science Citation Index (SCI), and later the Social Sciences Citation Index (SSCI) and the Arts and Humanities Citation Index (AHCI). The first automated citation indexing was done by CiteSeer in 1997 and was patented. Other sources for such data include Google Scholar, Elsevier's Scopus, and the National Institutes of Health's iCite.
Scopus is Elsevier’s abstract and citation database launched in 2004. Scopus covers nearly 36,377 titles from approximately 11,678 publishers, of which 34,346 are peer-reviewed journals in top-level subject fields: life sciences, social sciences, physical sciences and health sciences. It covers three types of sources: book series, journals, and trade journals. All journals covered in the Scopus database are reviewed for sufficiently high quality each year according to four types of numerical quality measure for each title; those are h-Index, CiteScore, SJR and SNIP .Searches in Scopus also incorporate searches of patent databases.
Physical Review Letters (PRL), established in 1958, is a peer-reviewed, scientific journal that is published 52 times per year by the American Physical Society. As also confirmed by various measurement standards, which include the Journal Citation Reports impact factor and the journal h-index proposed by Google Scholar, many physicists and other scientists consider Physical Review Letters to be one of the most prestigious journals in the field of physics.
Proceedings of the Royal Society is the parent title of two scientific journals published by the Royal Society. Originally a single journal, it was split into two separate journals in 1905:
The Institute for Scientific Information (ISI) was an academic publishing service, founded by Eugene Garfield in Philadelphia in 1956. ISI offered scientometric and bibliographic database services. Its specialty was citation indexing and analysis, a field pioneered by Garfield.
The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly average number of citations of articles published in the last two years in a given journal. It is frequently used as a proxy for the relative importance of a journal within its field; journals with higher impact factor values are often deemed to be more important, or carry more intrinsic prestige in their respective fields, than those with lower values.
Mathematical Reviews is a journal published by the American Mathematical Society (AMS) that contains brief synopses, and in some cases evaluations, of many articles in mathematics, statistics, and theoretical computer science. The AMS also publishes an associated online bibliographic database called MathSciNet which contains an electronic version of Mathematical Reviews and additionally contains citation information for over 3.5 million items as of 2018.
Google Scholar is a freely accessible web search engine that indexes the full text or metadata of scholarly literature across an array of publishing formats and disciplines. Released in beta in November 2004, the Google Scholar index includes most peer-reviewed online academic journals and books, conference papers, theses and dissertations, preprints, abstracts, technical reports, and other scholarly literature, including court opinions and patents. While Google does not publish the size of Google Scholar's database, scientometric researchers estimated it to contain roughly 389 million documents including articles, citations and patents making it the world's largest academic search engine in January 2018. Previously, the size was estimated at 160 million documents as of May 2014. An earlier statistical estimate published in PLOS ONE using a Mark and recapture method estimated approximately 80–90% coverage of all articles published in English with an estimate of 100 million. This estimate also determined how many documents were freely available on the web.
The Bulletin of the American Mathematical Society is a quarterly mathematical journal published by the American Mathematical Society.
The Corruption Perceptions Index (CPI) is an index published annually by Berlin-based Transparency International since 1995 which ranks countries "by their perceived levels of public sector corruption, as determined by expert assessments and opinion surveys." The CPI generally defines corruption as "the misuse of public power for private benefit".
Ibis, subtitled the International Journal of Avian Science, is the peer-reviewed scientific journal of the British Ornithologists' Union. It was established in 1859. Topics covered include ecology, conservation, behaviour, palaeontology, and taxonomy of birds. The editor-in-chief is Dominic J. McCafferty. The journal is published by Wiley-Blackwell in print and online. It is available free on the internet for institutions in the developing world through the OARE scheme.
Proceedings of the American Mathematical Society is a monthly peer-reviewed scientific journal of mathematics published by the American Mathematical Society. As a requirement, all articles must be at most 15 printed pages.
Zootaxa is a peer-reviewed scientific mega journal for animal taxonomists. It is published by Magnolia Press. The journal was established by Zhi-Qiang Zhang in 2001 and new issues are published multiple times a week. As of December 2012 more than 26,300 new taxa have been described in the journal. Print and online versions are available.
Index Medicus (IM) is a curated subset of MEDLINE, which is a bibliographic database of life science and biomedical science information, principally scientific journal articles. From 1879 to 2004, Index Medicus was a comprehensive bibliographic index of such articles in the form of a print index or its onscreen equivalent. Medical history experts have said of Index Medicus that it is “America's greatest contribution to medical knowledge.”
Journal Citation Reports (JCR) is an annual publication by Clarivate Analytics. It has been integrated with the Web of Science and is accessed from the Web of Science-Core Collections. It provides information about academic journals in the natural sciences and social sciences, including impact factors. The JCR was originally published as a part of Science Citation Index. Currently, the JCR, as a distinct service, is based on citations compiled from the Science Citation Index Expanded and the Social Sciences Citation Index.
Embase is a biomedical and pharmacological bibliographic database of published literature designed to support information managers and pharmacovigilance in complying with the regulatory requirements of a licensed drug. Embase, produced by Elsevier, contains over 32 million records from over 8,500 currently published journals from 1947 to the present. Through its international coverage, daily updates, and drug indexing with EMTREE, Embase enables tracking and retrieval of drug information in the published literature. Each record is fully indexed and Articles in Press are available for some records and In Process are available for all records, ahead of full indexing. Embase's international coverage expands across biomedical journals from 95 countries and is available through a number of database vendors.
Current Contents is a rapid alerting service database from Clarivate Analytics, formerly the Institute for Scientific Information and Thomson Reuters. It is published online and in several different printed subject sections.
Acta Crystallographica is a series of peer-reviewed scientific journals, with articles centred on crystallography, published by the International Union of Crystallography (IUCr). Originally established in 1948 as a single journal called Acta Crystallographica, there are now six independent Acta Crystallographica titles:
Today in China, there are more than 8,000 academic journals, of which more than 4,600 can be considered scientific. About 1,400 cover health science.
The Global Lepidoptera Names Index (LepIndex) is a searchable database maintained by the Department of Entomology at the Natural History Museum, London.
