I wonder if there are any search engines dedicated to indexing these kinds of libraries. I know there's a decent one just for scihub, but it would be awesome if I could do a Google-style search that returned the contents of books, magazines and journal articles instead of just websites.
There is the Imperial Library of Trantor: https://trantor.is/ They offer a clearnet and a hidden service .onion incase you don’t want ISPs blocking access to it.
I don't search for websites based on their titles...