Hughes, G. E., & Cresswell, M. J. (1984). A companion to modal logic. Methuen.
Chicago Edition CitationHughes, G. E., and M. J. Cresswell. A Companion to Modal Logic. London ; New York: Methuen, 1984.
MLA Edition CitationHughes, G. E., and M. J. Cresswell. A Companion to Modal Logic. Methuen, 1984.
Warning: These citations may not always be 100% accurate.