Wagner, R. H. (1978). Man and the environment. (3rd ed.). W W Norton.
Dyfyniad Arddull ChicagoWagner, Richard H. Man and the Environment. 3rd ed. New York: W W Norton, 1978.
Dyfyniad MLAWagner, Richard H. Man and the Environment. 3rd ed. W W Norton, 1978.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.