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 1961, 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). American Chemical Society converted its printed Chemical Abstract Service into internet-accessible SciFinder in 2008. The first automated citation indexing was done by CiteSeer in 1997 and was patented. Other sources for such data include Google Scholar, Microsoft Academic, 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 database Lexis-Nexis, albeit with a limited functionality.
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 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.
ScienceDirect is a website which provides access to a large bibliographic database of scientific and medical publications of the Dutch publisher Elsevier. It hosts over 18 million pieces of content from more than 4,000 academic journals and 30,000 e-books of this publisher. The access to the full-text requires subscription, while the bibliographic metadata is free to read. ScienceDirect is operated by Elsevier. It was launched in March 1997.
Organic Letters is a biweekly peer-reviewed scientific journal covering research in organic chemistry. It was established in 1999 and is published by the American Chemical Society. In 2014, the journal moved to a hybrid open access publishing model. The founding editor-in-chief was Amos Smith. Since 2019, Erick M. Carreira serves as the editor-in-chief. The journal is abstracted and indexed in: the Science Citation Index Expanded, Scopus, Academic Search Premier, BIOSIS Previews, Chemical Abstracts Service, EMBASE, and MEDLINE.
PLOS Genetics is a peer-reviewed open access scientific journal established in 2005 and published by the Public Library of Science. The founding editor-in-chief was Wayne N. Frankel. The current editors-in-chief are Gregory S. Barsh and Gregory P. Copenhaver. The journal covers research on all aspects of genetics and genomics.
Environmental Research Letters is a quarterly, peer-reviewed, open-access, scientific journal covering research on all aspects of environmental science. It is published by IOP Publishing. The editor-in-chief is Daniel Kammen.
College & Research Libraries is a bimonthly peer-reviewed academic journal published by the Association of College and Research Libraries.
The American Journal of Translational Research is an open-access medical journal published by e-Century Publishing Corporation. The journal covers translational research of medical science and the relevant biomedical research areas. It was established in 2009. The editor-in-chief is Wen-Hwa Lee. The journal's main focus is original clinical and experimental research articles, but it also publishes review articles, editorials, hypotheses, letters to the editor, and meeting reports.
Human Technology is an open-access peer-reviewed academic journal focusing on the interaction between people and technology. As of September 2021, the journal is published by the Centre of Sociological Research in Szczecin, Poland. Previously, the journal was co-published by the Agora Center and the University of Jyväskylä (2005-2016), and then by the Open Science Centre and the University of Jyväskylä (2017-2021). Initially, the journal published biannually; it has been published three times a year since 2018.
San Francisco Estuary and Watershed Science is a quarterly peer-reviewed open access scientific journal published by the California Digital Library covering research about the science and resource management of the San Francisco Bay, the Sacramento–San Joaquin River Delta, and the upstream watersheds. The journal was established in October 2003 and receives administrative and financial support from the John Muir Institute of the Environment and the Delta Stewardship Council. The editor-in-chief is Samuel N. Luoma.
The Journal of Political Ecology is an annual open access peer-reviewed academic journal covering political ecology. It was established in 1994 as one of the first open access journals in the social sciences, by James B. Greenberg and Thomas K. Park, to experiment with online formats and to showcase new work in the emerging field of political ecology. The current editors-in-chief are Simon P.J. Batterbury and Casey Walsh. There is an international editorial board.
eco.mont – Journal on Protected Mountain Areas Research and Management is a peer-reviewed open access scientific journal on mountain research in protected areas.
RSC Advances is an online-only peer-reviewed scientific journal covering research on all aspects of the chemical sciences. It was established in 2011 and is published by the Royal Society of Chemistry. The editor-in-chief is Russell J. Cox.
Molecular Autism is a peer-reviewed open-access medical journal covering research on the cause, biology, and treatment of autism and related neurodevelopmental disorders. The editors-in-chief are Simon Baron-Cohen and Joseph Buxbaum. The journal was established in 2010 and is published by BioMed Central.
IEEE Access is a peer-reviewed open-access scientific journal published by the Institute of Electrical and Electronics Engineers (IEEE). It was established in 2013 and covers all IEEE fields of interest. The founding editor-in-chief was Michael Pecht and the current editor-in-chief is Derek Abbott. The journal won a PROSE Award in 2015 for the best new journal in science, technology, engineering, and mathematics.
Aging is a bimonthly peer-reviewed open access bio-medical journal covering research on all aspects of gerontology. The journal was established in 2009 and is published by Impact Journals. The editors-in-chief are Jan Vijg, David Andrew Sinclair, Vera Gorbunova, Judith Campisi, Mikhail V. Blagosklonny.
Perspectives on Terrorism (PT) is a quarterly peer-reviewed, open-access online academic journal, covering political violence, terrorism and counter-terrorism, It is published jointly by the International Centre for Counter-Terrorism, in collaboration with Leiden University and the Handa Centre for the Study of Terrorism and Political Violence at the University of St Andrews.
Glossa: A Journal of General Linguistics is a peer-reviewed open access academic journal covering general linguistics. It was established in 2016. The journal is published by the Open Library of Humanities and the editor-in-chief is Johan Rooryck.
Research in Number Theory is a peer-reviewed mathematics journal covering number theory and arithmetic geometry. The editors-in-chief are Jennifer Balakrishnan, Florian Luca, Ken Ono, and Andrew Sutherland. It was established in 2015 as a full open access journal, but is now a hybrid open access journal, published by Springer Science+Business Media.
