Apps, Roy <br/><br/>
The top secret history of codes and codebreaking / 
Roy Apps. 
 - London :  Wayland,  2018. 
 - 32 p. 
<br/><br/><label>ISBN: </label>9780750298841 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Code breaking.<br/>Ciphers--Juvenile literature.
<br/><br/><label>Dewey Class. No.: </label>652.8