Cunningham, W. P., & Cunningham, M. A. (2012). Environmental science: A global concern (12th ed.). McGraw Hill.
Dyfyniad Arddull ChicagoCunningham, William P., and Marry Ann Cunningham. Environmental Science: A Global Concern. 12th ed. New York: McGraw Hill, 2012.
Dyfyniad MLACunningham, William P., and Marry Ann Cunningham. Environmental Science: A Global Concern. 12th ed. McGraw Hill, 2012.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.