Please take into consideration that some of the documents or books you want might be copyrighted. So it would be best to do the right thing and "purchase" these items.
Give the authors or existing copyright owner their compensation for all their hard work. Such as: Joseph F. Zygmunt, Edmond Gruss, Duane Magnani, Barbara Harrison, and so forth.
I thought you wanted old stuff already released, but couldn't find.
Atlantis!