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