Singh, G., & Inderjeet Kaur Sethi. (1992). Topics and terms in enviornmental science. Commonwealth.
Dyfyniad Arddull ChicagoSingh, Gurcharan, and Inderjeet Kaur Sethi. Topics and Terms in Enviornmental Science. New Delhi: Commonwealth, 1992.
Dyfyniad MLASingh, Gurcharan, and Inderjeet Kaur Sethi. Topics and Terms in Enviornmental Science. Commonwealth, 1992.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.