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Dworkin MB, Shrutkowski A, Dworkin-Rastl E.Dworkin MB, et al.Proc Natl Acad Sci U S A. 1985 Nov;82(22):7636-40. doi: 10.1073/pnas.82.22.7636.Proc Natl Acad Sci U S A. 1985.PMID: 2415967Free PMC article.