| Type | Book |
|---|---|
| By | Carter, Frank (Frank L.), author. |
| Languages | English |
| Edition | Second edition, revised and enlarged. |
| Publisher | Bletchley : Bletchley Park Trust, 2001. |
| Physical Description | 40 pages : illustrations ; 21 cm. |
| Subjects | Cryptography. | World War, 1939-1945. |
| Holdings |
|