APA citiranje

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

Trích dẫn kiểu Chicago

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

MLA citiranje

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