In the off-topic forum there is a list of books recommended by Elon Musk. One of them, "Ignition! An Informal History of Liquid Rocket Propellants" by John D Clark, is great reading for SpaceX enthusiasts. It is out of print and used copies are very expensive, but there is a PDF on-line. See this off-topic post:
9 Books That Elon Musk Thinks Everyone Should Read
GSP
9 Books That Elon Musk Thinks Everyone Should Read
GSP