There are three out-of-print books by John Sack. Frankly, they're out of print because he didn't much like them. If you insist, you can find them at used book stores. They are:
The Butcher: The Ascent of Yerupaja. Six college students climb the highest unclimbed mountain in the Americas.
From Here to Shimbashi. The misadventures of PFC Sack in the United States, Korea and Japan during the Korean War.
The Man-Eating Machine. An early attempt to write what's written much better in Fingerprint.