Karpagam, M. (1999). Environmental economics: A textbook (Rev. ed.). Sterling Publishers.
Cita Chicago (17th ed.)Karpagam, M. Environmental Economics: A Textbook. Rev. ed. New Delhi: Sterling Publishers, 1999.
Cita MLA (9th ed.)Karpagam, M. Environmental Economics: A Textbook. Rev. ed. Sterling Publishers, 1999.
Atenció: Aquestes cites poden no estar 100% correctes.