United Nations Environmental Program. (1987). State of the Environment: The state of the world environment. United Nations Environmental Program.
Style de citation Chicago (17e éd.)United Nations Environmental Program. State of the Environment: The State of the World Environment. Nairobi, Kenya: United Nations Environmental Program, 1987.
Style de citation MLA (9e éd.)United Nations Environmental Program. State of the Environment: The State of the World Environment. United Nations Environmental Program, 1987.
Attention : ces citations peuvent ne pas être correctes à 100%.