APA (7th ed.) Citation

Langer, W. L., Hedges, J. B., & Plietz, K. J. (1940). An encyclopedia of world history: Ancient, medieval, and modern, chronologically arranged. Houghton Mifflin.

Chicago Style (17th ed.) Citation

Langer, William L., James Blaine Hedges, and Karl Julius Plietz. An Encyclopedia of World History: Ancient, Medieval, and Modern, Chronologically Arranged. Boston: Houghton Mifflin, 1940.

MLA (9th ed.) Citation

Langer, William L., et al. An Encyclopedia of World History: Ancient, Medieval, and Modern, Chronologically Arranged. Houghton Mifflin, 1940.