Cita APA

Billington, R. A. 1., & Ridge, M. (1982). Westward expansion: A history of the American frontier (5. edition.). New York: Macmillan Publishing Co., INC..

Citación estilo Chicago

Billington, Ray Allen 1903-1981, y M. Ridge. Westward Expansion: A History of the American Frontier. 5. edition. New York: Macmillan Publishing Co., INC., 1982.

Cita MLA

Billington, Ray Allen 1903-1981, y M. Ridge. Westward Expansion: A History of the American Frontier. 5. edition. New York: Macmillan Publishing Co., INC., 1982.