APA (7th ed.) Citation

Feys, R. (1965). Modal logics. E. Nauwelaerts.

Chicago Style (17th ed.) Citation

Feys, Robert. Modal Logics. Lovaina: E. Nauwelaerts, 1965.

MLA (9th ed.) Citation

Feys, Robert. Modal Logics. E. Nauwelaerts, 1965.