I want to master German via reading e-books. I was thinking about the classic works of psychology. At best I'd like to read the works of Sigmund Freud and Erich Fromm in original. I was searching the internet, but I've found the links to the articles about the authors, and not their books.
I think that the licences for these books should have already expired, at least when in comes to Freud, so they should be also available in e-book format (at best, PDF format).