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Sheron N, Bird G, Goka J, Alexander G, Williams R.Sheron N, et al.Clin Exp Immunol. 1991 Jun;84(3):449-53.Clin Exp Immunol. 1991.PMID: 2044224Free PMC article.
Bird GL, Sheron N, Goka AK, Alexander GJ, Williams RS.Bird GL, et al.Ann Intern Med. 1990 Jun 15;112(12):917-20. doi: 10.7326/0003-4819-112-12-917.Ann Intern Med. 1990.PMID: 2339855
Bird G, Senaldi G, Panos M, Rolando N, Alexander G, Vergani D, Williams R.Bird G, et al.Gut. 1992 Mar;33(3):307-11. doi: 10.1136/gut.33.3.307.Gut. 1992.PMID: 1568647Free PMC article.