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Campbell NR, Burgess E, Taylor G, Wilson E, Cléroux J, Fodor JG, Leiter L, Spence JD.Campbell NR, et al. Among authors: spence jd.CMAJ. 1999 May 4;160(9):1341-3.CMAJ. 1999.PMID: 10333841Free PMC article.No abstract available.
Spence JD, Wong DG, Melendez LJ, Nichol PM, Brown JD.Spence JD, et al.Can Med Assoc J. 1984 Dec 15;131(12):1457-60.Can Med Assoc J. 1984.PMID: 6498701Free PMC article.Clinical Trial.