Purchase an autographed hardcover copy of Natural Prophets right now direct from the author for the discounted price of $19.95 + $4.00 shipping.
Natural Prophets (ISBN-13: 978-1-62336-179-2) is also available through the usual online booksellers as either hardcover or e-book.
NOTE: E-book contains these enhancements: 46 photos, research bibliography, expanded Index with 170 additions.