APA (7e ed.) Bronvermelding

United Nations Environmental Program. (1987). State of the Environment: The state of the world environment. United Nations Environmental Program.

Chicago (17e ed.) Bronvermelding

United Nations Environmental Program. State of the Environment: The State of the World Environment. Nairobi, Kenya: United Nations Environmental Program, 1987.

MLA (9e ed.) Bronvermelding

United Nations Environmental Program. State of the Environment: The State of the World Environment. United Nations Environmental Program, 1987.