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Schaap-Nutt A, D'Angelo C, Scull MA, Amaro-Carambot E, Nishio M, Pickles RJ, Collins PL, Murphy BR, Schmidt AC.Schaap-Nutt A, et al.Virology. 2010 Feb 20;397(2):285-98. doi: 10.1016/j.virol.2009.11.018. Epub 2009 Dec 7.Virology. 2010.PMID: 19969320Free PMC article.