CORONAVIRUS UPDATE: The library is closed effective Tuesday, March 24th. Continuing services will include: access to online materials; reference, class or research consultations; and assistance with securing expanded online access to curriculum-based and/or research materials. For more information see the Georgetown Libraries COVID-19 Updates and Resources page.
If you have an article and are looking for an open access version of it, try one of the options below. Neither of these services has 100% coverage of OA scholarship, but both are easy to use and provide access to a high percentage of materials in institutional repositories and on preprint servers.
Open Access Button - Enter an article's URL, DOI, citation, title, PMC ID, or PubMed ID to search for an OA version of the article - You can also search for datasets with the Open Access Button - A browser extension is also available - click on "Get the browser extension" link from the Open Access Button's homepage - If your article is not found, Open Access Button will give you an option to request the article from the author
Unpaywall - A browser extension for Chrome and Firefox that searches for open access versions of an articles
In 2019, the Washington Resarch Library Consortium (WRLC), of which Georgetown University is a member, joined the Open Textbook Network to support and promote the use of open textbooks.
Federal Agencies (info from the University of Minnesota Libraries) Policies vary somewhat from agency to agency; many allow for a 12-month embargo period before being made publicly available in an open access repository.