APA استشهاد

World Health Organization. Geneva. (1997). Nitrogen Oxides (2nd ed.). WHO.

استشهاد بنمط شيكاغو

World Health Organization. Geneva. Nitrogen Oxides. 2nd ed. Geneva: WHO, 1997.

MLA استشهاد

World Health Organization. Geneva. Nitrogen Oxides. 2nd ed. WHO, 1997.