APA (7th ed.) Citation

Ayer, A. J. (1972). The problem of knowledge (Reprint.). Penguin Books.

Chicago Style (17th ed.) Citation

Ayer, Alfred J. The Problem of Knowledge. Reprint. Harmondsworth, Middlesex [u.a.]: Penguin Books, 1972.

MLA (9th ed.) Citation

Ayer, Alfred J. The Problem of Knowledge. Reprint. Penguin Books, 1972.