APA (7th ed.) Citation

Ryan, J. C., & Elkin, V. (1992). Life support: Conserving biological diversity. Worldwatch Institute.

Chicago Style (17th ed.) Citation

Ryan, John C., and Vicki Elkin. Life Support: Conserving Biological Diversity. Washington, D.C: Worldwatch Institute, 1992.

MLA (9th ed.) Citation

Ryan, John C., and Vicki Elkin. Life Support: Conserving Biological Diversity. Worldwatch Institute, 1992.