APA aipamena

Hughes, G. E., & Cresswell, M. J. (1972). An introduction to modal logic. Methuen.

Chicago Style aipamena

Hughes, G. E., and M. J. Cresswell. An Introduction to Modal Logic. London: Methuen, 1972.

MLA aipamena

Hughes, G. E., and M. J. Cresswell. An Introduction to Modal Logic. Methuen, 1972.