World health Organization. (2004). Air quality guidelines,Global update 2005: Particulate matter, ozone nitrogen dioxide and sulfur dioxide. World Health Organization.
Chicago-Zitierstil (17. Ausg.)World health Organization. Air Quality Guidelines,Global Update 2005: Particulate Matter, Ozone Nitrogen Dioxide and Sulfur Dioxide. copenhagen: World Health Organization, 2004.
MLA-Zitierstil (8. Ausg.)World health Organization. Air Quality Guidelines,Global Update 2005: Particulate Matter, Ozone Nitrogen Dioxide and Sulfur Dioxide. World Health Organization, 2004.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.