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LoGiudice K, Ostfeld RS, Schmidt KA, Keesing F.LoGiudice K, et al. Among authors: keesing f.Proc Natl Acad Sci U S A. 2003 Jan 21;100(2):567-71. doi: 10.1073/pnas.0233733100. Epub 2003 Jan 13.Proc Natl Acad Sci U S A. 2003.PMID: 12525705Free PMC article.