While many of following databases are indexed by Unpaywall, Open Access Button and/or OA.mg, it may also be worth searching some of the following databases directly.
- CORE (COnnecting REpositories): As the world’s largest aggregator of open access research, CORE provides access to millions of full-text articles from a global network of over 10,000 institutional and subject repositories. Open Access Button directly uses CORE in its searches.
- SSRN (Social Science Research Network): This is a premier open-access repository containing over 1.6 million research papers and preprints in the social sciences, including extensive subject networks for leadership, management, and nonprofit studies.
- BASE (Bielefeld Academic Search Engine). Covers over 315 million documents with about 60% being open access. Open Access Button directly uses BASE in its searches.
- RePEc (Research Papers in Economics): With over 4.4 million indexed works, RePEc is a vital resource for research at the intersection of economics, business, and public policy, directly relevant to students studying organizational strategy and nonprofit financial management.
- ERIC (Education Resources Information Center): Sponsored by the U.S. Department of Education, ERIC is the world’s largest digital library for education research, indexing over 1.6 million records.
- Open Access Theses and Dissertations (OATD): An index of over 6.6 million graduate theses and dissertations from more than 1,100 institutions worldwide.
- PubMed: The premier biomedical literature database from the National Institutes of Health, offering over 39 million citations and abstracts vital for research in addiction and health-related fields, with about one-third being available as open access.
- GlobeEthicsLib (GEL) – launched in 2008 by Globethics.net, offers free access to over 700,000 texts, documents, articles and other resources. Focused on “Dialogue, reflection and action for responsible leadership.” Register for free to access full text documents, journals, reference books and eBooks.
- Open Access Digital Theological Library with over 480,000 ebooks and 50 million articles.
- Theological Commons at Princeton Seminary with over 164,000 items.
- Directory of Open Access Journals (DOAJ): The largest directory of its kind, providing access to over 11.5 million articles from more than 21,000 peer-reviewed open access journals.
- The Internet Archive: The Internet Archive contains a wide range of free content, including public domain books provided by Project Gutenberg.