United Nations Environmental Program. (1987). State of the Environment: The state of the world environment. United Nations Environmental Program.
Цитирование в стиле Чикаго (17-е изд.)United Nations Environmental Program. State of the Environment: The State of the World Environment. Nairobi, Kenya: United Nations Environmental Program, 1987.
Цитирование MLA (9-е изд.)United Nations Environmental Program. State of the Environment: The State of the World Environment. United Nations Environmental Program, 1987.
Предупреждение: эти цитированмия не могут быть всегда правильны на 100%.