APA (7th ed.) Zitazioa

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

Chicago Style (17th ed.) Zitazioa

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

MLA (9th ed.) Zitazioa

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