00933cam a2200253 4500 388578422 TxAuBib 20050425120000.0 730321s1972||||||||||||||||||||||||eng|u 72082218 9780671652012 lib. bdg. $9.99 067165201X lib. bdg. $9.99 (OCoLC)162152 DLC DLC OCL BS3 TxAuBib Gardner, Martin, 1914-2010. Codes, ciphers, and secret writing. New York : Simon and Schuster, [1972] 96 p : illus ; 24 cm. Bibliography: p. 94-96. Explains in simple terms how to encode and decode messages in various ciphers, describes coding machines, and gives formulas for invisible ink. 20070321. Ciphers Juvenile literature. Ciphers.