APA (7th ed.) Citation

Taylor, A. J. P., & Roberts, J. M. (1968). History of the 20th century. Purnell.

Chicago Style (17th ed.) Citation

Taylor, A. J. P., and James Morris Roberts. History of the 20th Century. London: Purnell, 1968.

MLA (9th ed.) Citation

Taylor, A. J. P., and James Morris Roberts. History of the 20th Century. Purnell, 1968.