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Hwang SS, Smith VC, McCormick MC, Barfield WD.Hwang SS, et al.Matern Child Health J. 2011 Aug;15(6):722-9. doi: 10.1007/s10995-010-0643-2.Matern Child Health J. 2011.PMID: 20652385
Hwang SS, Smith VC, McCormick MC, Barfield WD.Hwang SS, et al.Matern Child Health J. 2012 Nov;16(8):1688-95. doi: 10.1007/s10995-011-0870-1.Matern Child Health J. 2012.PMID: 21847677Free PMC article.