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Efird JT, O'Neal WT, Bolin P Jr, Davies SW, O'Neal JB, Anderson CA, Ferguson TB, Chitwood WR, Kypson AP.Efird JT, et al.Int J Environ Res Public Health. 2013 Sep 6;10(9):4175-85. doi: 10.3390/ijerph10094175.Int J Environ Res Public Health. 2013.PMID: 24018839Free PMC article.