Pettifor Audrey, McCoy Sandra I, Padian Nancy
Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA.
Lancet. 2012 Apr 7;379(9823):1280-2. doi: 10.1016/S0140-6736(12)60036-1. Epub 2012 Feb 15.