World Health Organization. (2000). Air quality guidelines for europe (2nd-ed.). World Health Organization.
Chicago-Zitierstil (17. Ausg.)World Health Organization. Air Quality Guidelines for Europe. 2nd-ed. Copenhagen: World Health Organization, 2000.
MLA-Zitierstil (8. Ausg.)World Health Organization. Air Quality Guidelines for Europe. 2nd-ed. World Health Organization, 2000.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.