Cita APA (7th ed.)

Nye, R. B., & Morpurgo, J. E. (1955). A history of the United States. Penguin Books.

Cita Chicago (17th ed.)

Nye, Russel B., i J. E. Morpurgo. A History of the United States. Harmondsworth: Penguin Books, 1955.

Cita MLA (9th ed.)

Nye, Russel B., i J. E. Morpurgo. A History of the United States. Penguin Books, 1955.