University of Oxford

David M. Shotton

![OpenCitations logo 50% with words
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In October 2015, I asked Silvio Peroni, my long-term colleague in the
development of the [SPAR
Ontologies](https://opencitations.wordpress.com/2010/10/14/introducing-the-semantic-publishing-and-referencing-spar-ontologies/),
to become Co-Director of the Open Citations Project, and to work with me
in taking forward the [prototype Open Citations
Corpus](https://opencitations.wordpress.com/2011/07/01/jisc-open-citations-project-%E2%80%93-final-project-blog-post/)
(OCC), originally developed at the University of Oxford with the support
of [Jisc](https://www.jisc.ac.uk/), with the aim of developing it into a
production service of real use to scholars.

The result is [OpenCitations](http://opencitations.net/), a new
instantiation of the OCC hosted by the Department of Computer Science
and Engineering of the University of Bologna, based on a new metadata
schema and employing several new technologies to automate the ingestion
of fresh citation metadata from authoritative sources.

Since the beginning of July 2016, OpenCitations has been ingesting and
processing accurate bibliographic references harvested from the
reference lists of scholarly papers available in [Europe PubMed
Central](http://europepmc.org/), enriched by metadata from
[Crossref](https://www.crossref.org/). These scholarly citation data are
described using the SPAR Ontologies according to the new OpenCitations
metadata document \[1\], and are published under a [Creative Commons
public domain dedication
(CC0)](https://creativecommons.org/publicdomain/zero/1.0/legalcode), so
that others may freely build upon, enhance and reuse them for any
purpose, without restriction under copyright or database law. We have
described the new OpenCitations Corpus, and the new software developed
by Silvio to create it, in \[2\].

OpenCitations is being continuously populated from the scholarly
literature, and, as of 30th March 2017, has ingested the references from
123,989 citing bibliographic resources, and contains information about
5,307,857 citation links to 3,469,648 cited resources.

The whole OCC is now available for querying (via SPARQL), and for
browsing by means of a very simple Web interface that shows only the
data about bibliographic entities (e.g.
<https://w3id.org/oc/corpus/br/1>). Additional more user-friendly
interfaces will be available in the coming months. The entire contents
of the OpenCitations Corpus (OCC) are also archived every month as [data
dumps](http://opencitations.net/download) that are made available online
through [Figshare](http://figshare.com/). Each dump comprises several
zip archives, each containing either data or provenance information of a
particular sub-dataset of the OCC.

Despite the fact that OpenCitations presently contains only a small
proportion of global citation data, it is important to realize that,
because of the very nature of scholarly citation, even this partial
coverage includes citations of the most important papers in every
biomedical field, these critical papers being characterized by the high
number of their inward citation links.

\[1\] Silvio Peroni, David Shotton (2016). Metadata for the
OpenCitations Corpus. figshare.
<https://dx.doi.org/10.6084/m9.figshare.3443876>

\[2\] Silvio Peroni, David Shotton, Fabio Vitali (2016). Freedom for
bibliographic references: OpenCitations arise. Proceedings of 2016
International Workshop on Linked Data for Information Extraction (LD4IE
2016): 32-43.  
<https://w3id.org/oc/paper/occ-lisc2016.html>


In October 2015, I asked Silvio Peroni, my long-term colleague in the development of the SPAR Ontologies, to become Co-Director of the Open Citations Project, and to work with me in taking forward the prototype Open Citations Corpus (OCC), originally developed at the University of Oxford with the support of Jisc, with the aim of developing it into a production service of real use to scholars.

Messaggi di Rogue Scholar

Open Citations is dead. Long live OpenCitations.