APA (7th ed.) Citation

Botkin, D. B., & Keller, E. (1987). Environmental studies: Earth as a living planet (2nd ed.). Merrill.

Chicago Style (17th ed.) Citation

Botkin, Daniel B., and Edward Keller. Environmental Studies: Earth as a Living Planet. 2nd ed. Columbus: Merrill, 1987.

MLA (9th ed.) Citation

Botkin, Daniel B., and Edward Keller. Environmental Studies: Earth as a Living Planet. 2nd ed. Merrill, 1987.