APA (7th ed.) Citation

Chellas, B. F. (1988). Modal logic: An introduction (repr.). Cambridge Univ. Press.

Chicago Style (17th ed.) Citation

Chellas, Brian F. Modal Logic: An Introduction. repr. Cambridge: Cambridge Univ. Press, 1988.

MLA (8th ed.) Citation

Chellas, Brian F. Modal Logic: An Introduction. repr. Cambridge Univ. Press, 1988.