APA (7th ed.) Citation

Freidel, F. B. (1960). America in the twentieth century. Knopf.

Chicago Style (17th ed.) Citation

Freidel, Frank Burt. America in the Twentieth Century. New York: Knopf, 1960.

MLA (9th ed.) Citation

Freidel, Frank Burt. America in the Twentieth Century. Knopf, 1960.