Dyfyniad APA

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

Dyfyniad Arddull Chicago

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

Dyfyniad MLA

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

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.