Table 2. Information gathered by the Program and corresponding data sources.

Multiple sources of information were used in this analysis, listed here.

Information	Source
Metadata: author(s), title, journal, ISSN, etc.	Unpaywall API
Open or closed	Unpaywall API
Type of access (Gold, Hybrid, Green, Closed, etc.)	Unpaywall API
Reprint/corresponding author	Web of Science and Scopus (CSV file)
Funders	Web of Science and Scopus (CSV file)
URLs of all repository versions	Unpaywall API
Type of ‘best open version’: published, preprint, postprint	Unpaywall API
APC/No APC	DOAJ (CSV file) GitHub site of Lisa Matthias (Freie Universität Berlin) https://github.com/lmatthia/publisher-oa-portfolios
Journal and publisher archiving rules and embargo periods	Sherpa/Romeo API
Citations	Crossref API