Cita APA (7a ed.)

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

Cita Chicago Style (17a ed.)

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

Cita MLA (9a ed.)

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