free public repositories of papers and books

I have been told that it is no longer needed to search for papers on regular libraries and libraries' services, as there is this web site which contains much more than even the best "legal" library www.sci-hub.cc

https://en.wikipedia.org/wiki/Sci-Hub Sci-Hub is an online search engine with over 58,000,000 academic papers and articles available for direct download, bypassing publisher paywalls. 

Similarly, for books, there is this web site www.bookzz.org BookZZ is one of the largest online libraries in the world. We aim to make literature accessible for everyone. Our site contains over 2 774 000 books.

Are you using them?