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Li C, Clarke S.Li C, et al. Among authors: clarke s.Proc Natl Acad Sci U S A. 1992 Oct 15;89(20):9885-9. doi: 10.1073/pnas.89.20.9885.Proc Natl Acad Sci U S A. 1992.PMID: 1409717Free PMC article.
Visick JE, Clarke S.Visick JE, et al. Among authors: clarke s.Mol Microbiol. 1995 Jun;16(5):835-45. doi: 10.1111/j.1365-2958.1995.tb02311.x.Mol Microbiol. 1995.PMID: 7476182Review.