For used copies, try the Internet databases of used book dealers. The three
most popular are:

http://www.abebooks.com/
http://www.interloc.com/
http://www.bibliofind.com/

ABE allows you to post "want" lists for free. If a shop then posts a title
later, you're automatically e-mailed a "match." This is how Amazon.com finds
their used books.

Some books of interest to us:

Vilhjalmur Stefansson's book _Cancer Disease of Civilization_ 1960; Hill
and Wang, New York, NY.

S. Boyd Eaton, M.D., M. Shostak, and M. Konner, M.D., Ph.D. 1988. "The
Paleolithic Prescription: A Program of Diet & Exercise and a Design
for Living". Harper & Row, New York. ISBN 0-06-015871-9

Dr. Walter Voegtlin's Stone Age Diet

Native Nutrition: Eating According to Ancestral Wisdom
by Ronald Schmid, N.D. Healing Arts Press.

Rindos, David. The Origins of Agriculture: An Evolutionary Perspective.
Orlando, Florida: Academic Press, 1984. xvii + 324 pp.