APA (7th ed.) Citation

Smullyan, R. M. (1961). Theory of formal systems. Princeton University Press.

Chicago Style (17th ed.) Citation

Smullyan, Raymond M. Theory of Formal Systems. Princeton: Princeton University Press, 1961.

MLA (9th ed.) Citation

Smullyan, Raymond M. Theory of Formal Systems. Princeton University Press, 1961.

Warning: These citations may not always be 100% accurate.