Rothman Kenneth J, Gallacher John E J, Hatch Elizabeth E
Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA, RTI Health Solutions, RTI International, Research Triangle Park, NC, USA and Institute of Primary Care and Public Health, Cardiff University, Cardiff, UK.
Int J Epidemiol. 2013 Aug;42(4):1012-4. doi: 10.1093/ije/dys223.