Antonisamy B, Raghupathy P, Christopher Solomon, Richard J, Rao P S S, Barker David J P, Fall Caroline H D
Department of Biostatistics, Christian Medical College, Vellore, India.
Int J Epidemiol. 2009 Jun;38(3):663-9. doi: 10.1093/ije/dyn159. Epub 2008 Aug 6.