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The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
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The https:// ensures that you are connecting to the
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Gemmell MA, Lawson JR, Roberts MG.Gemmell MA, et al.Bull World Health Organ. 1986;64(3):333-9.Bull World Health Organ. 1986.PMID: 3490317Free PMC article.