It is a good book, have it in hard cover. Feynman indirectly wrote quite a few graduate level texts such as The Theory of Fundamental Processes, Statistical Me

It is a good book, have it in hard cover. Feynman indirectly wrote quite a few graduate level texts such as The Theory of Fundamental Processes, Statistical Mechanics Lecture Notes and Photon-hadron Interactions which are compilations of lecture notes re-written in book form. There is also one on gravitation dating to the early 1960s.