World Health Organization. (2012). WHO guidelines on the pharmacological treatment of persisting pain in children with medical illness. World Health Organization.
Trích dẫn kiểu Chicago (xuất bản lần thứ 7)World Health Organization. WHO Guidelines on the Pharmacological Treatment of Persisting Pain in Children with Medical Illness. Geneva, Switzerland: World Health Organization, 2012.
Trích dẫn kiểu MLA (xuất bản lần thứ 8)World Health Organization. WHO Guidelines on the Pharmacological Treatment of Persisting Pain in Children with Medical Illness. World Health Organization, 2012.
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