Winterbotham, F. W.  1897- <br/><br/>
The Ultra secret / 
F. W. Winterbotham. 
 - 1st U.S. ed. 
 - New York :  Harper & Row,  c1974. 
 - xiii, 199 p. ;  22 cm. 
<br/><br/><label>ISBN: </label>0060146788 :  $8.95 
<br/><br/><label>LCCN: </label>74007826  
<br/><br/><label>Subjects--Personal Names: </label><br/>Winterbotham, F. W. 1897- 
<br/><br/><label>Subjects--Topical Terms: </label><br/>World War, 1939-1945--Cryptography.<br/>World War, 1939-1945--Secret service--Great Britain.<br/>World War, 1939-1945--Personal narratives, British.
<br/><br/><label>LC Class. No.: </label>D810.C88  / W56 1974 
<br/><br/><label>Dewey Class. No.: </label>940.54/86/41