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Krause A, Whu WZ, Xu Y, Joh J, Crystal RG, Worgall S.Krause A, et al. Among authors: worgall s.Vaccine. 2011 Mar 3;29(11):2131-9. doi: 10.1016/j.vaccine.2010.12.087. Epub 2011 Jan 6.Vaccine. 2011.PMID: 21215829Free PMC article.
Krause A, Xu Y, Ross S, Wu W, Joh J, Worgall S.Krause A, et al. Among authors: worgall s.Virol J. 2011 Jul 29;8:375. doi: 10.1186/1743-422X-8-375.Virol J. 2011.PMID: 21801372Free PMC article.