Dyfyniad APA

Botkin, D. B., & Keller, E. A. (2012). Environmental science: International student version (8th ed.). Wiley.

Dyfyniad Arddull Chicago

Botkin, Daniel B., and Edward A. Keller. Environmental Science: International Student Version. 8th ed. Hoboken, NJ ; New Delhi: Wiley, 2012.

Dyfyniad MLA

Botkin, Daniel B., and Edward A. Keller. Environmental Science: International Student Version. 8th ed. Wiley, 2012.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.