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Ploeg J, Black ME, Hutchison BG, Walter SD, Scott EA, Chambers LW.Ploeg J, et al.Can J Public Health. 1994 May-Jun;85(3):188-91.Can J Public Health. 1994.PMID: 7922964Clinical Trial.
Ploeg J, Hutchison B, Cressman G, Morgan B, Thompson D, Scott D, Mann E, Banko D, Hayward L, Grayson K.Ploeg J, et al.Perspectives. 2007 Spring;31(1):5-10.Perspectives. 2007.PMID: 17668826No abstract available.