APA (7th ed.) Citation

Keylor, W. R., & McGuire, M. (2007). The Encyclopedia of the modern world: 1900 to the present. Facts On File.

Chicago Style (17th ed.) Citation

Keylor, William R., and Michael McGuire. The Encyclopedia of the Modern World: 1900 to the Present. New York: Facts On File, 2007.

MLA (8th ed.) Citation

Keylor, William R., and Michael McGuire. The Encyclopedia of the Modern World: 1900 to the Present. Facts On File, 2007.