BOAI https://www.budapestopenaccessinitiative.org/
Wikipedia https://en.wikipedia.org/wiki/Open_access
Open Access Network https://open-access.network/en/information/open-access-primers/what-does-open-access-mean
Carnegie Mellon University, OA libguide https://guides.library.cmu.edu/openaccess/home (with permission)
David Wiley, Open Content https://openedreader.org/openedreader/open-content
The Council for Online Learning Excellence (COLE), Open Educational Resources: Basics and Beyond https://open.ocolearnok.org/learnoer/front-matter/introduction/
Creative Commons "Unit 5: CC for Academic Librarians" https://certificates.creativecommons.org/cccertedu/chapter/6-2-oer-open-textbooks-open-courses/