title: The optimal duration of exclusive breastfeeding: results of a WHO systematic review.
mesh_terms: D001942:Breast Feeding; D002657:Child Development; D003906:Developing Countries; D005260:Female; D006801:Humans; D007223:Infant; D007227:Infant Nutritional Physiological Phenomena; D007231:Infant, Newborn; D008297:Male; D013997:Time Factors; D014944:World Health Organization