Dyfyniad APA

World Health Organization. (1990). Use of essential drugs. World Health Organization.

Dyfyniad Arddull Chicago

World Health Organization. Use of Essential Drugs. Geneva: World Health Organization, 1990.

Dyfyniad MLA

World Health Organization. Use of Essential Drugs. World Health Organization, 1990.

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