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Bax T, Sheppard BC, Crass RA.Bax T, et al. Among authors: crass ra.Am Fam Physician. 1999 Jan 1;59(1):143-56.Am Fam Physician. 1999.Corrected and republished in: Am Fam Physician. 1999 Feb 15;59(4):893-906..PMID: 9917580Free article.Corrected and republished.Review.