APA aipamena

Speth,James Gustave. (2004). Global Environmental Challenges. Orient Longman.

Chicago Style aipamena

Speth,James Gustave. Global Environmental Challenges. New Delhi: Orient Longman, 2004.

MLA aipamena

Speth,James Gustave. Global Environmental Challenges. Orient Longman, 2004.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.