Cita APA (7a ed.)

Ayer, A. J. (1969). Philosophical essays. MacMillan.

Cita Chicago Style (17a ed.)

Ayer, A. J. Philosophical Essays. London [etc.]: MacMillan, 1969.

Cita MLA (9a ed.)

Ayer, A. J. Philosophical Essays. MacMillan, 1969.