May 26, 2022

Milestones: Initiative for Open Citations (I4OC) Reports Open References at Crossref Exceed 50%

From the Initiative for Open Citations (I4OC) Blog:

The analyses show that, of 956,050,193 references from journal articles stored at Crossref, 486,041,671 (50.84%) are now in the category “Open”, and are freely available for third parties to download and use for any purpose.

This is a significant milestone for the Initiative for Open Citations (I4OC,, which since early 2017 has been campaigning for scholarly publishers to open their reference lists, and a major gain for the world of open scholarship.


Crossref has records of 93,184,372 works with DOIs, of which 69,699,144 (74.80%) are journal articles and 23,485,228 (25.20%) are works that are not journal articles (i.e. book chapters, proceedings articles, datasets, etc.).

Crossref stores 1,075,133,743 references from all 93,184,372 works, averaging 11.54 references per work.

More Statistics in the Complete I40C Blog Post

About Gary Price

Gary Price ( is a librarian, writer, consultant, and frequent conference speaker based in the Washington D.C. metro area. Before launching INFOdocket, Price and Shirl Kennedy were the founders and senior editors at ResourceShelf and DocuTicker for 10 years. From 2006-2009 he was Director of Online Information Services at, and is currently a contributing editor at Search Engine Land.