Cita APA (7th ed.)

Comfort, W. (1974). The theory of ultrafilters. Springer-Verlag.

Cita Chicago (17th ed.)

Comfort, W.W. The Theory of Ultrafilters. New York: Springer-Verlag, 1974.

Cita MLA (9th ed.)

Comfort, W.W. The Theory of Ultrafilters. Springer-Verlag, 1974.