Dyfyniad APA
Botkin, D. B., & Keller, E. A. (1998). Environmental science: Earth as a living planet (2nd ed.). J. Wiley & Sons.
Dyfyniad Arddull Chicago
Botkin, Daniel B., and Edward A. Keller. Environmental Science: Earth as a Living Planet. 2nd ed. New York: J. Wiley & Sons, 1998.
Dyfyniad MLA
Botkin, Daniel B., and Edward A. Keller. Environmental Science: Earth as a Living Planet. 2nd ed. J. Wiley & Sons, 1998.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.