Welcome to the OpenCitations homepage!

OpenCitations is a scholarly infrastructure organization dedicated to open scholarship and the publication of open bibliographic and citation data by the use of Semantic Web (Linked Data) technologies, and engaged in advocacy for semantic publishing and open citations. It provides the OpenCitations Data Model and the SPAR (Semantic Publishing and Referencing) Ontologies for encoding scholarly bibliographic and citation data in RDF, and open software of generic applicability for searching, browsing and providing APIs over RDF triplestores. It has developed the OpenCitations Corpus (OCC) of open downloadable bibliographic and citation data recorded in RDF, and a system and resolution service for Open Citation Identifiers (OCIs), and it is currently developing a number of Open Citation Indexes using the data openly available in third-party bibliographic databases.

OpenCitations is currently working to expand and improve the supporting infrastructure of the OpenCitations Corpus (OCC), our open repository of scholarly citation data made available under a Creative Commons public domain dedication, which provides in RDF accurate citation information (bibliographic references) harvested from the scholarly literature. These are described using the SPAR Ontologies according to the OpenCitations Data Model, and are made freely available so that others may freely build upon, enhance and reuse them for any purpose, without restriction under copyright or database law.

The OCC is being continuously populated from the scholarly literature.

As of December 12, 2019, the OCC has ingested the references from
326743 citing bibliographic resources
and contains information about 13964148 citation links
to 7565367 cited resources.

The contents of OCC can be explored by humans using the OCC's search interface, created by means of OSCAR. The search interface takes an alphanumeric string representing an identifier (DOI, ORCID), author name or work title (or part thereof) as input to identify bibliographic works and their authors, references and citations. The returned results can then be browsed using OSCAR's associated browse interface, i.e. LUCINDA. Programmatic access to the OCC is available either using its SPARQL endpoint. Metadata for individual bibliographic entities can be accessed via a simple Web form using their individual URIs (e.g. https://w3id.org/oc/corpus/br/1).

In addition, recently OpenCitations has started to build several Open Citation Indexes using the data available in particular bibliographic databases. The first of these is the COCI, the OpenCitations Index of Crossref open DOI-to-DOI references, a new RDF dataset of around 450 million citations. All the data in each Index are searchable and browsable with the tools and interfaces already used in the OCC. In addition, it is also possible to query its data by using a REST API implemented by means of RAMOSE.

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