Keller, D. R. (2010). Environmental ethics: The big questions. Wiley-Blackwell.
Čikaški stil citiranjaKeller, David R. Environmental Ethics: The Big Questions. U.S.A.: Wiley-Blackwell, 2010.
MLA način citiranjaKeller, David R. Environmental Ethics: The Big Questions. Wiley-Blackwell, 2010.
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