Albert H. Beiler - Games - 1964 - 349 pages
Number theory proves to be a virtually inexhaustible source of intriguing puzzle problems. Includes divisors, perfect numbers, the congruences of Gauss, scales of notation, the ...
Charles C. Mann - History - 2005 - 465 pages
A Groundbreaking Study that radically alters our understanding of the Americas before the arrival of the Europeans in 1492.
Petr Beckmann - Mathematics - 1989 - 200 pages
Documents the calculation, numerical value, and use of the ratio from 2000 B.C. to the modern computer age, detailing social conditions in eras when progress was made.