Dyfyniad APA

World Health Organization. (2011). Atlas of headache disorders and resources in the world 2011. World Health Organization.

Dyfyniad Arddull Chicago

World Health Organization. Atlas of Headache Disorders and Resources in the World 2011. Geneva, Switzerland: World Health Organization, 2011.

Dyfyniad MLA

World Health Organization. Atlas of Headache Disorders and Resources in the World 2011. World Health Organization, 2011.

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