Cita APA

Cunningham, W. P., & Cunningham, M. A. (2012). Environmental science: A global concern (Twelfth ed.). New York: McGraw-Hill Companies, Inc..

Citación estilo Chicago

Cunningham, William P., y Mary Ann Cunningham. Environmental Science: A Global Concern. Twelfth ed. New York: McGraw-Hill Companies, Inc., 2012.

Cita MLA

Cunningham, William P., y Mary Ann Cunningham. Environmental Science: A Global Concern. Twelfth ed. New York: McGraw-Hill Companies, Inc., 2012.