The Imperial Library of Trantor has a huge variety of--copyrighted--books, available free for download. Most of the books are about programming, but they have a wide variety fo science fiction, history and political material as well.
All the books are in epub format, if you don't have a epub reader i recommend FBReader which is Free and Open Source and available for nearly every OS: Android, Windows, Linux, MacOS etc. https://fbreader.org/
Of course, you can only access the library via Tor, so you will need the Tor Browser which you can download here. https://www.torproject.org/download/download-easy.html.en