एपीए उद्धरण

(1991). Caring for the earth: A strategy for sustainable living. Switzerland: IUCN/ENEP/WWE.

शिकागो स्टाइल उद्धरण

Caring for the Earth: A Strategy for Sustainable Living. Switzerland: IUCN/ENEP/WWE, 1991.

एमएलए उद्धरण

Caring for the Earth: A Strategy for Sustainable Living. Switzerland: IUCN/ENEP/WWE, 1991.