If you’re interested in using one source to find Open Access publications in repositories around the world, I invite you to check out WorldCat.
WorldCat is the world’s largest network of library content and services. Perform your searches for books, articles, photographic images, audio, video, etc. in WorldCat and discover materials in libraries worldwide. You can also discover freely available digital materials found in repositories worldwide. Repositories such as the HathiTrust, Internet Archive, and institutional repositories like IUScholarWorks.
Once you’ve performed your search, use the refinement tools on the left navigation side bar to narrow your results to ‘Internet Resources.’ From here, you will notice that many of the records come from a database called ‘OAIster‘ (OA meaning Open Access) and have an orange ‘View Now’ link associated. Certainly take a look at the full record by clicking on the item’s title, but the view now link takes you to a repository that is storing the material openly for the world to access.
Check it out and please ask us or your library’s reference staff for help if you have questions. WorldCat is a remarkable search engine. Be sure to take advantage of creating an account and managing your resources within WorldCat.