Just bought (for me) a new book "Pedal Crush" (c 2019). Over 360 pages of all the various types of guitar effects, their history, how they work and interviews with the inventors and users. Hundreds of photos of various pedals and brief descriptions. A highly recommended book. It's price though, $80+ delivered. You can't yet get it though Amazon. O bought it from, I think, the publisher. Sweetwater has it as well.