World health Organization. (2004). Air quality guidelines,Global update 2005: Particulate matter, ozone nitrogen dioxide and sulfur dioxide. World Health Organization.
Chicago (17e ed.) BronvermeldingWorld health Organization. Air Quality Guidelines,Global Update 2005: Particulate Matter, Ozone Nitrogen Dioxide and Sulfur Dioxide. copenhagen: World Health Organization, 2004.
MLA (8e ed.) BronvermeldingWorld health Organization. Air Quality Guidelines,Global Update 2005: Particulate Matter, Ozone Nitrogen Dioxide and Sulfur Dioxide. World Health Organization, 2004.
Let op: Deze citaties zijn niet altijd 100% accuraat.