APA-viite (7. p.)
Global Environmental Monitoring System. (1991). Urban air pollution. United nations environment health.
Chicago-viite (17. p.)
Global Environmental Monitoring System. Urban Air Pollution. Nairobi: United nations environment health, 1991.
MLA-viite (9. p.)
Global Environmental Monitoring System. Urban Air Pollution. United nations environment health, 1991.
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