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Donaldson RM, Fox K, Rickards AF.Donaldson RM, et al.Br Med J (Clin Res Ed). 1983 Feb 26;286(6366):667-71. doi: 10.1136/bmj.286.6366.667.Br Med J (Clin Res Ed). 1983.PMID: 6402196Free PMC article.