Cita APA (7a ed.)

Beard, C. A., & Bagley, W. C. (1920). A first book in american history. The Macmillan company.

Cita Chicago Style (17a ed.)

Beard, Charles Austin, y William C. Bagley. A First Book in American History. New York: The Macmillan company, 1920.

Cita MLA (9a ed.)

Beard, Charles Austin, y William C. Bagley. A First Book in American History. The Macmillan company, 1920.