Groenwold R H H, Rovers M M
Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Stratenum 6.131, PO Box 85500, 3508 GA Utrecht, The Netherlands.
J Clin Epidemiol. 2010 Oct;63(10):1059-60. doi: 10.1016/j.jclinepi.2010.04.013.