APA (7th ed.) Citation

Porter, B. (2006). Empire and superempire: Britain, America and the world. Yale University Press.

Chicago Style (17th ed.) Citation

Porter, Bernard. Empire and Superempire: Britain, America and the World. New Haven, Conn.: Yale University Press, 2006.

MLA (9th ed.) Citation

Porter, Bernard. Empire and Superempire: Britain, America and the World. Yale University Press, 2006.