I stumbled across this biography while reading about Graham Farmelo's biography of Paul Dirac. http://epress.anu.edu.au/maverick/html/prelims.html Maverick Mathematician The Life and Science of J.E. Moyal It's interesting because there is an appendix with correspondence between Moyal and Dirac. http://epress.anu.edu.au/maverick/html/apb.html Appendix 2. P.A.M. Dirac – J. E. Moyal: Correspondence, 1944-1946. Basser Library, Australian Academy of Science, Canberra, MS 45/3/ Appendix 3. contains his paper -Quantum Mechanics as a Statistical Theory by J.E. Moyal Originally published in the Proceedings of the Cambridge Philosophical Society, Vol. 45, 1949. http://epress.anu.edu.au/maverick/pdf/app03.pdf Reproduced with permission of Cambridge University Press. Moyal was also an engineer.