APA (7th ed.) Citation

Curti, M., Shryock, R., Harrington, F. H., & Cochran, T. G. (1950). An American history. Harper.

Chicago Style (17th ed.) Citation

Curti, Merle, Richard Shryock, Fred Harvey Harrington, and Thomas G. Cochran. An American History. New York: Harper, 1950.

MLA (9th ed.) Citation

Curti, Merle, et al. An American History. Harper, 1950.