Messages in Code (Hello Out There)
Publisher: Tandem Library
Published: October 2001
Language: eng
Format: School & Library Binding
ISBN-13: 9780808584261
Subjects: Language Arts - General; Cryptography; Juvenile Nonfiction; Children's Books/Ages 9-12 Nonfiction; Children: Grades 2-3; Science & Nature - General; Ciphers; Juvenile literature
First sentence: When you first think about codes, you probably think of secret messages being sent by spies and soldiers in wartime.