Dyfyniad APA

Botkin, D. B., & Keller, E. A. (2003). Environmental science: Earth as a living planet (4th ed.). New York: Wiley.

Dyfyniad Arddull Chicago

Botkin, Daniel B., và Edward A. Keller. Environmental Science: Earth As a Living Planet. 4th ed. New York: Wiley, 2003.

Dyfyniad MLA

Botkin, Daniel B., và Edward A. Keller. Environmental Science: Earth As a Living Planet. 4th ed. New York: Wiley, 2003.

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