Mel, H X <br/><br/>
Cryptography decrypted 
H. X. Mel, Doris Baker. 
 - Boston  Addison Wesley  2000 
 - xx, 352p.: ill.; 24cm. 
<br/><br/><label>ISBN: </label>0-201-61647-5. 
<br/><br/><label>Dewey Class. No.: </label>005.8  / M53C