APA (7th ed.) Citation

Ehrlich, P. R., Ehrlich, A. H., & Holdren, J. P. (1977). Ecoscience: Population, resources, environment (2. ed.). Freeman.

Chicago Style (17th ed.) Citation

Ehrlich, Paul R., Anne H. Ehrlich, and John Paul Holdren. Ecoscience: Population, Resources, Environment. 2. ed. San Francisco: Freeman, 1977.

MLA (9th ed.) Citation

Ehrlich, Paul R., et al. Ecoscience: Population, Resources, Environment. 2. ed. Freeman, 1977.