World Health Organization. Geneva. (1997). Nitrogen Oxides (2nd ed.). WHO.
Chicago Style aipamenaWorld Health Organization. Geneva. Nitrogen Oxides. 2nd ed. Geneva: WHO, 1997.
MLA aipamenaWorld Health Organization. Geneva. Nitrogen Oxides. 2nd ed. WHO, 1997.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.