Cita APA

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

Citación estilo Chicago

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

Cita MLA

Ehrlich, Paul R., et al. Ecoscience: Population, Resources, Environment. W. H. Freeman, 1977.