1.
If P, then Q. London: Routledge; 1989.
If P, then Q. London : Routledge, 4 mai 1989. ISBN 0-415-07994-2
Sanford David Hawley. (1989). If P, then Q: Conditionals and the foundations of reasoning. Routledge.
MLA (8th ed.) CitationSanford David Hawley. If P, Then Q: Conditionals and the Foundations of Reasoning. Routledge, 1989.
Warning: These citations may not always be 100% accurate.