According to the Scholarly Publishing and Academic Resources Coalition (SPARC),"Open Access is the free, immediate, online availability of research articles." Listed below are sources of Open Access articles, books, journals, and repositories that are freely available to anyone, provided they are not used for commercial purposes:
The Internet Archive has a collection of freely available, downloadable Google Books.
Repositories are digital collections of data, research and other intellectual products of university communities or other institutions. The content of repositories is sometimes, but not always, Open Access.