Cunningham, W. P., & Cunningham, M. A. (2012). Environmental science: A global concern (Twelfth ed.). New York: McGraw-Hill Companies, Inc..
Παραπομπή Chicago StyleCunningham, William P., και Mary Ann Cunningham. Environmental Science: A Global Concern. Twelfth ed. New York: McGraw-Hill Companies, Inc., 2012.
Παραπομπή MLACunningham, William P., και Mary Ann Cunningham. Environmental Science: A Global Concern. Twelfth ed. New York: McGraw-Hill Companies, Inc., 2012.
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