• are the links that knit together our scientific and cultural knowledge;
• are primary data that provide both provenance and an explanation for how we know facts;
• allow us to attribute and credit scientific contributions, and they enable the evaluation of research and its impacts;
• are the most important vehicle for the discovery, dissemination, and evaluation of all scholarly knowledge.

As the number of scholarly publications is estimated to double every nine years, citations – and the computational systems that track them – enable researchers and the public to keep abreast of significant developments in any given field.

For this to be possible, it is essential to have unrestricted access to bibliographic and citation data in machine-readable form.

Citation data are not usually freely available to access, they are often subject to inconsistent, hard-to-parse licenses, and they are usually not machine-readable...

Many publishers currently deposit reference lists from their journal articles to Crossref as part of their participation in Crossref’s Cited-by service. To open their references, along with the other bibliographic metadata that publishers send to Crossref, publishers need to turn on reference distribution for all of the Digital Object Identifier (DOI) prefixes they manage. This step allows references within the Crossref members’ articles to be distributed without restriction through all of Crossref's Metadata Delivery services, including the REST API and bulk metadata dumps, to any interested party. See for additional information on reference distribution and on how to participate in Crossref’s Cited-by service.

Key benefits arising from a fully open citation dataset include:

• The establishment of a global public web of linked scholarly citation data to enhance the discoverability of published content, both subscription access and open access.
• The ability to build new services over the open citation data, for the benefit of publishers, researchers, funding agencies, academic institutions and the general public, as well as enhancing existing services.
• The creation of a public citation graph to explore connections between knowledge fields, and to follow the evolution of ideas and scholarly disciplines.