Cita APA (7th ed.)

Ayer, A. J. (1976). The central questions of philosophy. Penguin Books.

Cita Chicago (17th ed.)

Ayer, A. J. The Central Questions of Philosophy. Harmondsworth, Middlesex: Penguin Books, 1976.

Cita MLA (9th ed.)

Ayer, A. J. The Central Questions of Philosophy. Penguin Books, 1976.