Botkin, D. B., & Keller, E. A. (2002). Environmental science: Earth as a living planet (Fourth Edition.). John Wiley & Sons.
Chicago-viite (17. p.)Botkin, Daniel B., ja Edward A. Keller. Environmental Science: Earth as a Living Planet. Fourth Edition. New York: John Wiley & Sons, 2002.
MLA-viite (9. p.)Botkin, Daniel B., ja Edward A. Keller. Environmental Science: Earth as a Living Planet. Fourth Edition. John Wiley & Sons, 2002.
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