Winterbotham, Frederick William.

The Ultra secret / F. W. Winterbotham. - 1st U.S. ed. - New York : Harper & Row, c1974. - xiii, 199 p. ; 22 cm.

ISBN: 0060146788 :

LCCN: 74007826 //r892

Subjects--Personal Names:
Winterbotham, Frederick William.

Subjects--Topical Terms:
World War, 1939-1945--Cryptography.
World War, 1939-1945--Personal narratives, British.
World War, 1939-1945--Secret Service--Great Britain.

LC Class. No.: D810.C88 / W56 1974

Dewey Class. No.: 940.54/86/41