Loads of Codes and Secret CiphersBook - 1984
Discusses and provides practice in making and breaking codes and ciphers, as well as in building simple coding devices to transmit secret messages.
Publisher: New York : Macmillan ; London : Collier Macmillan, c1984.
Branch Call Number: J 001.5436 Janeczko
Characteristics: ix, 108 p. :,ill. ;,24 cm.