एपीए उद्धरण

Karpagam,M. (1991). Environmental economics: A text book. Sterling Publishers Pvt. Ltd.

शिकागो स्टाइल उद्धरण

Karpagam,M. Environmental Economics: A Text Book. New Delhi: Sterling Publishers Pvt. Ltd, 1991.

एमएलए उद्धरण

Karpagam,M. Environmental Economics: A Text Book. Sterling Publishers Pvt. Ltd, 1991.