Cita APA (7th ed.)

EHRLICH, P. R., EHRLICH, A. H., & HOLDREN, J. P. (1973). Human ecology: Problems and solutions. W.H. Freeman.

Cita Chicago (17th ed.)

EHRLICH, Paul R., Anne H. EHRLICH, i John P. HOLDREN. Human Ecology: Problems and Solutions. San Francisco: W.H. Freeman, 1973.

Cita MLA (9th ed.)

EHRLICH, Paul R., et al. Human Ecology: Problems and Solutions. W.H. Freeman, 1973.