Cunningham, W. P., & Cunningham, M. A. (2006). Principles of environmental science: Inquiry and applications (3rd ed.). Dubuque, IA: McGraw-Hill.
Chicago-tyylinen lähdeviittausCunningham, William P., and Mary Ann Cunningham. Principles of Environmental Science: Inquiry and Applications. 3rd ed. Dubuque, IA: McGraw-Hill, 2006.
MLA-viiteCunningham, William P., and Mary Ann Cunningham. Principles of Environmental Science: Inquiry and Applications. 3rd ed. Dubuque, IA: McGraw-Hill, 2006.
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