Asthana, D. K. (2005). Environment: Problems and solutions (2nd ed.). S. Chand & Co.
Dyfyniad Arddull ChicagoAsthana, D. K. Environment: Problems and Solutions. 2nd ed. New Delhi: S. Chand & Co, 2005.
Dyfyniad MLAAsthana, D. K. Environment: Problems and Solutions. 2nd ed. S. Chand & Co, 2005.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.