Hughes, G. E., & Cresswell, M. J. (1968). An introduction to modal logic. London: Methuen.
Chicago Style CitationHughes, George Edward, and M. J. Cresswell. An Introduction to Modal Logic. London: Methuen, 1968.
MLA CitationHughes, George Edward, and M. J. Cresswell. An Introduction to Modal Logic. London: Methuen, 1968.
Warning: These citations may not always be 100% accurate.