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Giles GG, Marks R, Foley P.Giles GG, et al.Br Med J (Clin Res Ed). 1988 Jan 2;296(6614):13-7. doi: 10.1136/bmj.296.6614.13.Br Med J (Clin Res Ed). 1988.PMID: 3122913Free PMC article.