Citation indices

academic search service by Google

Scopus is a scientific abstract and citation database, launched by the academic publisher Elsevier as a competitor to older Web of Science in 2004. The ensuing competition between the two databases has been characterized as "intense" and is considered to significantly benefit their users in terms of continuous improvement in coverage, search/analysis capabilities, but not in price. Free database The Lens completes the triad of main universal academic research databases.

catalog of citations

bibliographic database (1996-)

annual publication covering academic journals

measure of scientific influence of scholarly journals

citation index

bibliographic database for economics

citation index produced since 2015 by Thomson Reuters, and now by Clarivate Analytics

citation index product of Clarivate Analytics

collaboration between scholarly publishers, researchers, and other interested parties to promote the unrestricted availability of scholarly citation data

online database of profiles of scientists, scientific institutions, publications and projects

OpenCitations (established in 2010) is a project aiming to publish open bibliographic citation information in RDF. It produces the "OpenCitations Corpus" citation database in the process.