Cita APA (7a ed.)

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

Cita Chicago Style (17a ed.)

Ayer, A. J. The Central Questions of Philosophy. Harmondsworth [etc.]: Penguin Books, 1976.

Cita MLA (9a ed.)

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