WELSH , DOMINIC <br/><br/>
CODES AND CRYPTOGRAPHY 

 -  OXFORD : CLARENDON  1988 
 - 257 p. 
<br/><br/><label>ISBN: </label>0000198532873 
<br/><br/><label>Subjects--Topical Terms: </label><br/>CRYPTOGRAPHY
<br/><br/><label>Dewey Class. No.: </label>005.8  / W24