Billington, R. A. (1962). The Far Western frontier, 1830-1860. Harper & Row.
Cita Chicago (17th ed.)Billington, Ray Allen. The Far Western Frontier, 1830-1860. New York: Harper & Row, 1962.
Cita MLA (8th ed.)Billington, Ray Allen. The Far Western Frontier, 1830-1860. Harper & Row, 1962.
Atenció: Aquestes cites poden no estar 100% correctes.