I never did get to read all three but my grandmother had a set of Foxfire books that were quite a wealth of knowledge about all things survival related. I'm guessing they might be out of print by now...but it could be worth a look around.

Apart from that you might try checking in the "new age" section of a book store. The last time I was wandering around in a bookstore I seem to remember seeing some there as well.
Best of luck!