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Pappou I, Cammisa F Jr, Papadopoulos E, Frelinghuysen P, Girardi F.Pappou I, et al.SAS J. 2008 Jun 1;2(2):114-9. doi: 10.1016/SASJ-2007-0116-RR. eCollection 2008.SAS J. 2008.PMID: 25802611Free PMC article.