Open access literature

Examples of repositories to search directly


​Google scholar​

Searching for articles through Google Scholar will find them in well-indexed repositories. The repository versions are usually those deposited by the authors and may include versions prior to peer review. More information on Google Scholar & article searches.

​MIT catalogue​

Data from the Unpaywall ( database of open access journals and repositories is integrated into the MIT Libraries catalog (), which means an open accessversion of an article will appear as an option in search results if one is available.

​PubMed Central​



List of other disciplinary repositories


Browser extensions

You can find open access articles through browser extensions. These tools find legally available manuscript versions as well as final published articles when the journal allows it or the journal is open access.

​Open Access Button​

Enter an article’s URL, DOI, title, or other information on the OA Button website to find free, legal, open access versions. Or install the Chrome or Firefox extension, then click on it from a paywalled article to initiate a search for an open version and, when available, instantly get free access. When free access is not found, the service can contact the author directly to help them make the article available.


Directly search an open, legal database of millions of open access scholarly articles. Or install the Chrome or Firefox extension to connect to open access versions of paywalled articles. Unpaywall data is integrated into the MIT Libraries catalog, as well as Web of Science.