World Health Organization. Geneva. (1997). Nitrogen Oxides (2nd ed.). WHO.
Chicago Edition CitationWorld Health Organization. Geneva. Nitrogen Oxides. 2nd ed. Geneva: WHO, 1997.
Cita MLAWorld Health Organization. Geneva. Nitrogen Oxides. 2nd ed. WHO, 1997.
Atenció: Aquestes cites poden no estar 100% correctes.