Παραπομπή APA

Zeman, J. J. (1973). Modal logic: The Lewis-modal systems. Clarendon Press.

Παραπομπή Chicago Style

Zeman, J. Jay. Modal Logic: The Lewis-modal Systems. London: Clarendon Press, 1973.

Παραπομπή MLA

Zeman, J. Jay. Modal Logic: The Lewis-modal Systems. Clarendon Press, 1973.