APA (7th ed.) Citation

Keylor, W. R.. (1992). The twentieth-century world: An international history (2nd ed.). Oxford University Press.

Chicago Style (17th ed.) Citation

Keylor, William R. The Twentieth-century World: An International History. 2nd ed. New York Oxford: Oxford University Press, 1992.

MLA (9th ed.) Citation

Keylor, William R. The Twentieth-century World: An International History. 2nd ed. Oxford University Press, 1992.