Rationale Readers of this blog will be familiar with Open Citation Identifiers (OCIs), described in an earlier post and formally defined in [1]. OCIs enable bibliographic citations, treated as first class information entities, to be uniquely identified and referenced, and are used to identify the >624 million individual citations indexed in the latest release of COCI, the OpenCitations Index of Crossref open DOI-to-DOI citations, as

We are now proud to announce the third release of COCI, which contains more than 624 million DOI-to-DOI citation links coming from both ‘the ‘Open’ and the ‘Limited’ sets of Crossref reference data.

COCI, the OpenCitations Index of Crossref open DOI-to-DOI citations **Author(s) **Ivan Heibi – ivan.heibi2@unibo.it Digital Humanities Advanced Research Centre (DHARC), Department of Classical Philology and Italian Studies, University of Bologna, Bologna, Italy Silvio Peroni – silvio.peroni@unibo.it Digital Humanities Advanced Research Centre (DHARC), Department of Classical Philology and Italian Studies, University of Bologna,

Crowdsourcing open citations with CROCI An analysis of the current status of open citations, and a proposal **Author(s) **Ivan Heibi – ivan.heibi2@unibo.it Digital Humanities Advanced Research Centre (DHARC), Department of Classical Philology and Italian Studies, University of Bologna, Bologna, Italy Silvio Peroni – silvio.peroni@unibo.it Digital Humanities Advanced Research Centre (DHARC), Department of Classical Philology and

The OpenCitations Enhancement Project Final report for the Alfred P. Sloan Foundation Report period: 1st May 2017 – 30 November 2018.

As introduced in a previous blog post, COCI is the OpenCitations Index of Crossref open DOI-to-DOI references, all released as CC0 material.

In a previous series of blog posts we proposed the treatment of bibliographic citations as first-class data entities, permitting citations to be endowed with descriptive properties.

OpenCitations [1], the EXCITE Project [2] and Europe PubMed Central [3] are pleased to announce a Workshop on Open Citations at the University of Bologna in Bologna, Italy [4] on 3-5 September – https://workshop-oc.github.io. Format and topics Day One and Day Two: Formal presentations and discussions on the creation, availability, uses and applications of open bibliographic citations, and of bibliometric studies based upon

OpenCitations is very pleased to announce its collaboration with four new scholarly Research and Development projects that are early adopters of the recently updated OpenCitations Data Model, described in this blog post.

Requirements for citations to be treated as first-class data entities In my introductory blog post, I listed five requirements for the treatment of citations as first-class data entities.  The fifth and final of these requirements is that there must be a Web-based identifier resolution service that takes the citation identifier as input and returns a description of the citation.