1. Turing. A. M. 1937. On computable numbers, with an application to the Entscheidungs problem. Proc. London Math. Soc., (2) 42: 230 (in which he discusses the use of machines to solve mathematical problems).

2. Steiner, G. 1983. Machines and the man, The Sunday Times [of London], October 23: 42.

3. Welchman, G. The Hut Six Story: Breaking the Enigma Codes ( New York. 1982); F. H. Hinsley, E. E. Thomas, C. F. G. Ransom and R. C. Knight, British Intelligence in the Second World War, Volumes 1 and 2 ( London. 1979 and 1981).

4. See House of Commons Debates, 941 ( January 12, 1978), cols. 829 830.

5. The appendix to Josef Garlinski. Intercept: the Enigma War ( London, 1979).

6. Rejewsk, M. 1982. Mathematical Solution of the Enigma Cipher, Cryptologia. 6: 1.

7. Hinsley merely states that the British Bombe was of quite different design from the Polish, volume 1, 494.

8. Hinsley, volume 2, appendix 4.

9. Good, I. J. Studies in the History of Probability and Statistics XXXVII A. M. Turing's Statistical Work in World War II, Biometrika, 66 ( 1979) 393; Probability and the Weighing of Evidence ( London. 1950); and The Estimation of Probabilities. ( Cambridge MA. 1965) 18, 31, 32, 68.

10. Good, I. J. 1979. Biometrika 66: 393.

11. Good, I. J. and G. H. Toulmin. 1968. Coding theorems and weight of evidence. J. Inst. Maths.