Dyfyniad APA

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

Dyfyniad Arddull Chicago

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

Dyfyniad MLA

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

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