Codemaster
Subtitle: how to write and decode secret messages
By: by Marvin Miller
Contributors: Copyright Paperback Collection (Library of Congress)
Publisher: Scholastic
Published: 1998
Place of publication: New York
Language: eng
Number of pages: 69
Description: Learn the Pinhole code,the Inside-out code, the Mixed-up math code, the Pigpen code, and more.
Notes: These codes were previously published in Boy's Life magazine.

Reading level 4 ; ages 9 to 12.