The introduction in Chapter 1 says it all: “This manual has been written to help you…to travel, find water and food, shelter yourself from weather, and care for yourself if you become sick or injured…You can remain alive anywhere in the world when you keep your wits.”
(FM 21-76 Department of the Army Field Manual: Survival, 1970 edition, page 3)
I prefer to pay “economy” prices for my purchases of books (or anything else) when I can. I believe that I paid 25 cents for my copy at a garage sale (or was it the Salvation Army?), but it is also available for a reasonable price online at places like amazon.com.
From extracting water from vines to firemaking, this military survival guide contains no frivolous information: it reads like a technical manual because it is a technical manual! If a choice exists between purchasing this book or another, this is the book to choose!