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Stein AD, Wang M, Ramirez-Zea M, Flores R, Grajeda R, Melgar P, Ramakrishnan U, Martorell R.Stein AD, et al.Am J Epidemiol. 2006 Dec 15;164(12):1160-70. doi: 10.1093/aje/kwj328. Epub 2006 Oct 3.Am J Epidemiol. 2006.PMID: 17018700