Winterbotham, F. W.  1897- <br/><br/>
The ultra secret / 
F. W. Winterbotham 
 - London :  Weidenfeld And Nicolson,  c1975 
 - xiii, 199 p. ;  22 cm. 
<br/><br/> Includes index 
<br/><br/><label>ISBN: </label>0297768328 :  PND 3.25 
<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>Dewey Class. No.: </label>940.548