APA (7th ed.) Citation

Ayer, A. J. (1956). The problem of knowledge / A.J. Ayer. Penguin.

Chicago Style (17th ed.) Citation

Ayer, A. J. The Problem of Knowledge / A.J. Ayer. Harmondsworth: Penguin, 1956.

MLA (9th ed.) Citation

Ayer, A. J. The Problem of Knowledge / A.J. Ayer. Penguin, 1956.

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