APA (7th ed.) Citation

Hughes, G. E., & Cresswell, M. J. (1984). A companion to modal logic University paperbacks.

Chicago Style (17th ed.) Citation

Hughes, George Edward, and M. J. Cresswell. "A Companion to Modal Logic." University Paperbacks 1984.

MLA (9th ed.) Citation

Hughes, George Edward, and M. J. Cresswell. "A Companion to Modal Logic." University Paperbacks, 1984.