Tony Tanner - Thomas Pynchon (Methuen, 1982)

As a Pynchon fan, this book is almost compulsory reading. It helps to give some perspectives and interpretations of what is happening in Pynchon's novels. Trust me, it does not offer any clues to fully understand Pynchon, which is not the point, but at least it gives some fresh ideas and background facts that help clarify some things. 

Tanner's analysis dates from 1982, so the novels discussed in this short book, are "V", "The Crying Of Lot 49" and "Gravity's Rainbow". Some of Tanner's insights will make you want to read these novels again. 

Enjoy!