Cita APA (7th ed.)

Perman, R., Ma, Y., & McGilvray, J. (1996). Natural resource and environmental economics. Longman.

Cita Chicago (17th ed.)

Perman, Roger, Yue Ma, i James McGilvray. Natural Resource and Environmental Economics. New York: Longman, 1996.

Cita MLA (9th ed.)

Perman, Roger, et al. Natural Resource and Environmental Economics. Longman, 1996.