Counting Liberties
In the British Go Journals 102 through 120, Richard Hunter wrote a series on counting liberties. The first nine parts were adapted slightly and included in the Kiseido 2nd edition of Richard Bozulich's Second book of Go. A table summarizing the types of capturing races is to be found here.
The British Go Journal articles formed the basis of the book Counting Liberties and Winning Capturing Races by Slate and Shell. The contents have been expanded with additional examples and problems.