APA (7th ed.) Citation

Hughes, G. E., & Cresswell, M. J. (1977). An introduction to modal logic (repr.). Methuen.

Chicago Style (17th ed.) Citation

Hughes, George E., and Maxwell J. Cresswell. An Introduction to Modal Logic. repr. London: Methuen, 1977.

MLA (9th ed.) Citation

Hughes, George E., and Maxwell J. Cresswell. An Introduction to Modal Logic. repr. Methuen, 1977.