Kippenhahn R <br/><br/>
Code breaking : a history and exploration 

 - New York  University Press  1999 
 - 283p. : ill.   
<br/><br/> Includes bibliographical references and index. 
<br/><br/><label>ISBN: </label>8173712042 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Code breaking<br/>Cryptography