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Schiffer JT, Abu-Raddad L, Mark KE, Zhu J, Selke S, Koelle DM, Wald A, Corey L.Schiffer JT, et al.Proc Natl Acad Sci U S A. 2010 Nov 2;107(44):18973-8. doi: 10.1073/pnas.1006614107. Epub 2010 Oct 18.Proc Natl Acad Sci U S A. 2010.PMID: 20956313Free PMC article.