Cita APA

Ridge, M., & Billington, R. A. (1980). America's frontier story: A documentary history of westward expansion. R. E. Krieger Pub. Co..

Citación estilo Chicago

Ridge, Martin, and Ray Allen Billington. America's Frontier Story: A Documentary History of Westward Expansion. Huntington, N.Y: R. E. Krieger Pub. Co., 1980.

Cita MLA

Ridge, Martin, and Ray Allen Billington. America's Frontier Story: A Documentary History of Westward Expansion. R. E. Krieger Pub. Co., 1980.