CiTO, the Citation Typing Ontology, is used to record information about bibliographic citations (literature references) made in scholarly articles, including their nature, the rationale for their presence, and their frequency.
The latest version of CiTO is CiTO Version 1.6, published on 26 March 2010. CiTO is written in the Web Ontology Language OWL, uses the namespace purl.org/net/cito/, and is available from http://purl.org/net/cito/.
That site uses content negotiation to deliver to the user an OWLDoc Web version of the ontology if accessed via a Web browser, or the OWL ontology itself if accessed from an ontology management tool such as Protégé.
Work is currently being undertaken to harmonize CiTO with other ontologies describing bibliographies and the rhetorical structure of scientific discourse, starting with the SWAN Scientific Discourse Ontology.
In light of the evidence presented by Greenberg  showing how hypotheses are changed into established "facts" simply by the process of citation, it becomes vitally important that we are able to create citation networks more easily than at present, so that such distortions can be more easily detected and analysed. Publication of machine readable reference lists, marked up using CiTO, would assist that.
 Greenberg SA (2009). How citation distortions create unfounded authority: analysis of a citation network. BMJ 339:b2680, doi: 10.1136/bmj.b2680 (Published 21 July 2009).