Dyfyniad APA

World Health Organization. (2000). Air quality guidelines for europe (2nd-ed.). World Health Organization.

Dyfyniad Arddull Chicago

World Health Organization. Air Quality Guidelines for Europe. 2nd-ed. Copenhagen: World Health Organization, 2000.

Dyfyniad MLA

World Health Organization. Air Quality Guidelines for Europe. 2nd-ed. World Health Organization, 2000.

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