Abacus Bibliography

An Engineer and an Abacus
Bibliography

Belle S. Toole. "The Trusty Landmark." The Permian Historical Annual. XIII (December 1973).
Boyer, Carl B. A History of Mathematics. (Second Edition, Revised by Uta C. Merzbach) John Wiley & Sons, Inc., N.Y., 1991.
Ifrah, Georges. From One to Zero. Penguin Books, N.Y., 1981.