Decker, R. (2006). Volcanoes (4th ed.). Freeman.
Cita Chicago (17th ed.)Decker, Robert. Volcanoes. 4th ed. New York: Freeman, 2006.
Cita MLA (9th ed.)Decker, Robert. Volcanoes. 4th ed. Freeman, 2006.
Atenció: Aquestes cites poden no estar 100% correctes.