Reminder to be aware of darknet mirrors like I2P sites and Tor .onion services - domains aren’t controlled by a company so they can’t just be taken down by a legal request.
For z-lib, the Wikipedia article lists their .onion and I2P addresses (I haven’t verified them so check before bookmarking): https://en.wikipedia.org/wiki/Z-Library
Carl and the Aqua Team make their position on piracy very clear.
https://inv.us.projectsegfau.lt/watch?v=MCTlcJMCSpM