APA (7th ed.) Citation

Keylor, W. R. (2001). The twentieth century world: An international history (4. ed.). Oxford Univ. Press.

Chicago Style (17th ed.) Citation

Keylor, William R. The Twentieth Century World: An International History. 4. ed. New York [u.a.]: Oxford Univ. Press, 2001.

MLA (9th ed.) Citation

Keylor, William R. The Twentieth Century World: An International History. 4. ed. Oxford Univ. Press, 2001.