OpenCitations is an independent infrastructure organization for open scholarship dedicated to the publication of open bibliographic and citation data by the use of Semantic Web (Linked Data) technologies. It is also engaged in advocacy for open citations, particularly by organizing the Workshops for Open Citations and Scholarly Metadata, and in its role as a key founding member of the Initiative for Open Citations (I4OC) and the Initiative for Open Abstracts (I4OA).

OpenCitations espouses fully the founding principles of Open Science. It complies with the FAIR data principles by Force11 that data should be findable, accessible, interoperable and re-usable, and it complies with the recommendations of I4OC that citation data in particular should be structured, separable, and open. On the latter topic, OpenCitations has recently published a formal definition of an Open Citation, and has launched a system for globally unique and persistent identifiers (PIDs) for bibliographic citations – Open Citation Identifiers (OCIs).

The following publication is the canonical publication describing OpenCitations itself, as an infrastructure organization for open scholarship. The article describes OpenCitations and its datasets, tools, services and activities.

Silvio Peroni, David Shotton (2020). OpenCitations, an infrastructure organization for open scholarship. Quantitative Science Studies, 1(1): 428-444.

The OpenCitations Data Model (OCDM) is the metadata model used for the data stored in all the OpenCitations' datasets, described in

Marilena Daquino, Silvio Peroni, David Shotton (2020). The OpenCitations Data Model. Figshare.

The largest dataset created by OpenCitations is COCI, the OpenCitations Index of Crossref open DOI-to-DOI citations, an RDF dataset containing details of all the citations that are specified by the open references to DOI-identified works present in Crossref. COCI does not index Crossref references that are not open, nor Crossref open references to entities that lack DOIs. The citations available in COCI are treated as first-class data entities, with accompanying properties including the citations timespan, modelled according to the OpenCitations Data Model.

Currently, COCI contains information concerning 733,367,140 citations, and 59,455,917 bibliographic resources. COCI was most recently updated on 6 September 2020.

For an in-depth description of COCI, see:

Ivan Heibi, Silvio Peroni, David Shotton (2019). Software review: COCI, the OpenCitations Index of Crossref open DOI-to-DOI citations. Scientometrics, 121 (2): 1213-1228.

Project Author(s)

David Shotton; Silvio Peroni

Project Video

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