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Kadam UT, Schellevis FG, van der Windt DA, de Vet HC, Bouter LM, Croft PR.Kadam UT, et al.J Clin Epidemiol. 2008 Apr;61(4):386-393. doi: 10.1016/j.jclinepi.2007.05.014. Epub 2007 Oct 15.J Clin Epidemiol. 2008.PMID: 18313564