Cita APA (7a ed.)

Butterfield, H., & Watson, A. (1981). The origins of history. Eyre Methuen.

Cita Chicago Style (17a ed.)

Butterfield, Herbert, y Adam Watson. The Origins of History. London: Eyre Methuen, 1981.

Cita MLA (9a ed.)

Butterfield, Herbert, y Adam Watson. The Origins of History. Eyre Methuen, 1981.