Cunningham, W. P., & Cunningham, M. A. (2007). Principles of environmrntal science: Inquiry and applications (4th.). Tata McGraw-Hill.
Dyfyniad Arddull ChicagoCunningham, William P., and Mary Ann Cunningham. Principles of Environmrntal Science: Inquiry and Applications. 4th. New Delhi: Tata McGraw-Hill, 2007.
Dyfyniad MLACunningham, William P., and Mary Ann Cunningham. Principles of Environmrntal Science: Inquiry and Applications. 4th. Tata McGraw-Hill, 2007.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.