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Libby SJ, Goebel W, Ludwig A, Buchmeier N, Bowe F, Fang FC, Guiney DG, Songer JG, Heffron F.Libby SJ, et al. Among authors: songer jg.Proc Natl Acad Sci U S A. 1994 Jan 18;91(2):489-93. doi: 10.1073/pnas.91.2.489.Proc Natl Acad Sci U S A. 1994.PMID: 8290552Free PMC article.