Παραπομπή APA

Ballard, M., & Mathias, P. (1971). Revolutions and steam engines 1775 - 1815. Methuen.

Παραπομπή Chicago Style

Ballard, Martin, και Peter Mathias. Revolutions and Steam Engines 1775 - 1815. London: Methuen, 1971.

Παραπομπή MLA

Ballard, Martin, και Peter Mathias. Revolutions and Steam Engines 1775 - 1815. Methuen, 1971.