APA-referens (7:e uppl.)

Roberts, J. (1992). The penguin history of the world. Penguin.

Chicago-referens (17:e uppl.)

Roberts, J.M. The Penguin History of the World. 3rd.ed: Penguin, 1992.

MLA-referens (9:e uppl.)

Roberts, J.M. The Penguin History of the World. Penguin, 1992.