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Hoa NB, Sy DN, Nhung NV, Tiemersma EW, Borgdorff MW, Cobelens FG.Hoa NB, et al. Among authors: cobelens fg.Bull World Health Organ. 2010 Apr;88(4):273-80. doi: 10.2471/BLT.09.067801. Epub 2010 Feb 22.Bull World Health Organ. 2010.PMID: 20431791Free PMC article.