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Williams AF, Mayhew DR.Williams AF, et al.Am J Prev Med. 2008 Sep;35(3 Suppl):S324-33. doi: 10.1016/j.amepre.2008.06.015.Am J Prev Med. 2008.PMID: 18702990Review.
Williams AF, McCartt AT, Sims LB.Williams AF, et al.J Safety Res. 2016 Feb;56:9-15. doi: 10.1016/j.jsr.2015.11.006. Epub 2015 Dec 2.J Safety Res. 2016.PMID: 26875159