Niche, but the book Property-Based Testing with PropEr, Erlang, and Elixir [1] taught me a lot. It might be the only dead-tree book on PBT. If you don't know what it is, here's a short video on it [2], it's basically a tool to automate tests and automatically simplify (shrink) the failing cases.

1. https://propertesting.com/

2. https://www.youtube.com/watch?v=AfaNEebCDos