Impossible to pick just one.
Several by Jeff Cooper make the list.

So does "Handgunner's Guide" by Chic Gaylord.

"The Snubby Revolver" by Ed Lovette is another.

So is "Quick Or Dead" by Willam L. Cassidy.

"Hit The White Part" by Massad Ayoob is one of the books I read
when I was learning to shoot pins.

"Pin Shooting: A Complete Guide" by Mitchell A. Ota is a sentimental
favorite. It was the first thing I won playing trivia at the 1991
Second Chance Bowling Pin Shoot in Central Lake, MI.

I could go on...