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Chapman DP, Liu Y, Presley-Cantrell LR, Edwards VJ, Wheaton AG, Perry GS, Croft JB.Chapman DP, et al.BMC Public Health. 2013 Jan 3;13:3. doi: 10.1186/1471-2458-13-3.BMC Public Health. 2013.PMID: 23286392Free PMC article.