Tanya Welz1, Kobus Herbst. 1. Africa Centre for Health and Population Studies, University of kwaZulu-Natal, Mtubatuba, South Africa. tanyawelz@btinternet.com
Authors: Sheldon R Morris; Susan J Little; Terry Cunningham; Richard S Garfein; Douglas D Richman; Davey M Smith Journal: Ann Intern Med Date: 2010-06-15 Impact factor: 25.391