Dyfyniad APA

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

Dyfyniad Arddull Chicago

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

Dyfyniad MLA

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

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.