Botkin, D. B., & Keller, E. A. (2003). Environmental Science: Earth as a Living Planet (4th ed.). John Wiley & Sons.
Cita Chicago (17th ed.)Botkin, Daniel B., i Edward A. Keller. Environmental Science: Earth as a Living Planet. 4th ed. New York: John Wiley & Sons, 2003.
Cita MLA (9th ed.)Botkin, Daniel B., i Edward A. Keller. Environmental Science: Earth as a Living Planet. 4th ed. John Wiley & Sons, 2003.
Atenció: Aquestes cites poden no estar 100% correctes.