How to write codes and send secret messages
By: by John Peterson. Illustrated by Bernice Myers.
Contributors: Myers, Bernice, illus.
Publisher: Four Winds Press
Published: 1970
Place of publication: New York
Language: eng
Number of pages: 64
Subjects: Ciphers -- Juvenile literature; Ciphers
Description: Explains how to write and decipher space codes, hidden word codes, and alphabet codes and gives formulas for invisible ink. Includes suggestions for delivering coded messages.