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Norris FH, Smith RA, Denys EH.Norris FH, et al.Br Med J (Clin Res Ed). 1985 Jul 27;291(6490):259-62. doi: 10.1136/bmj.291.6490.259.Br Med J (Clin Res Ed). 1985.PMID: 3926148Free PMC article.