APA (7th ed.) Citation

Langer, W. L. (1987). An encyclopedia of world history: Ancient, medieval, and modern (New extended ed.). Harrap Galey Press.

Chicago Style (17th ed.) Citation

Langer, William L. An Encyclopedia of World History: Ancient, Medieval, and Modern. New extended ed. London: Harrap Galey Press, 1987.

MLA (9th ed.) Citation

Langer, William L. An Encyclopedia of World History: Ancient, Medieval, and Modern. New extended ed. Harrap Galey Press, 1987.