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Holmes EC, Zhang LQ, Simmonds P, Ludlam CA, Brown AJ.Holmes EC, et al.Proc Natl Acad Sci U S A. 1992 Jun 1;89(11):4835-9. doi: 10.1073/pnas.89.11.4835.Proc Natl Acad Sci U S A. 1992.PMID: 1594583Free PMC article.