Botkin, D. B., & Keller, E. A. (2003). Environmental Science: Earth as a Living Planet (4th ed.). John Wiley & Sons.
Chicago Style (17th ed.) ZitazioaBotkin, Daniel B., eta Edward A. Keller. Environmental Science: Earth as a Living Planet. 4th ed. New York: John Wiley & Sons, 2003.
MLA (9th ed.) ZitazioaBotkin, Daniel B., eta Edward A. Keller. Environmental Science: Earth as a Living Planet. 4th ed. John Wiley & Sons, 2003.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.