APA (7th ed.) Citation

Brenan, G., Partridge, R., & Fielding, X. (1986). Best of friends: The Brenan-Partridge letters. Chatto & Windus.

Chicago Style (17th ed.) Citation

Brenan, Gerald, Ralph Partridge, and Xan Fielding. Best of Friends: The Brenan-Partridge Letters. London: Chatto & Windus, 1986.

MLA (9th ed.) Citation

Brenan, Gerald, et al. Best of Friends: The Brenan-Partridge Letters. Chatto & Windus, 1986.