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Persson BC, Gustafsson C, Berg DE, Björk GR.Persson BC, et al. Among authors: bjork gr.Proc Natl Acad Sci U S A. 1992 May 1;89(9):3995-8. doi: 10.1073/pnas.89.9.3995.Proc Natl Acad Sci U S A. 1992.PMID: 1373891Free PMC article.