APA (7th ed.) Citation

Koestler, A. (1979). Janus: A summing up. Picador.

Chicago Style (17th ed.) Citation

Koestler, Arthur. Janus: A Summing Up. London: Picador, 1979.

MLA (8th ed.) Citation

Koestler, Arthur. Janus: A Summing Up. Picador, 1979.