APA aipamena

Perman,Roger. (1999). Natural resource and environmental economics. Longman.

Chicago Style aipamena

Perman,Roger. Natural Resource and Environmental Economics. London: Longman, 1999.

MLA aipamena

Perman,Roger. Natural Resource and Environmental Economics. Longman, 1999.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.