APA (7th ed.) Citation

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

Chicago Style (17th ed.) Citation

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

MLA (9th ed.) Citation

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