The Probable and The Provable. : Oxford University Press, 1977-12-08. Oxford Scholarship Online. 2011-10-03. Date Accessed 19 Jun. 2013 <http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780198244127.001.0001/acprof-9780198244127>.
(1977-12-08). The Probable and The Provable. : Oxford University Press. Retrieved 19 Jun. 2013, from http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780198244127.001.0001/acprof-9780198244127.
The Probable and The Provable. : Oxford University Press, 1977-12-08. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780198244127.001.0001/acprof-9780198244127.
Cohen LJ. The Probable and The Provable. Oxford University Press; 1977. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780198244127.001.0001/acprof-9780198244127. Accessed June 19, 2013.