Unfortunately, I borrowed this book from a friend when I read it, so I no longer have it as a reference. I wanted to write a brief summary of the book anyways, because it provided me with an actionable playing strategy that I still use to this day.
The author of this book is actually a tennis instructor who has studied ways to implement mental strategies not only in tennis, but in the workplace, and other sports. His application to the game of golf is wonderful in my perspective, and could be a huge help to anyone who suffers from "don't hit it in the lake," or any timid thoughts during the swing. If you want to learn more about his teachings, Gallwey talks about it on his website here.
I loved this book because it kept everything so simple, eliminating the confusion and doubt that comes from many mental game books. I highly recommend it!
Here is the print version of the book.