Bhutta Zulfiqar A, Yousafzai Aisha K, Zipursky Alvin
Division of Women and Child Health, Department of Paediatrics and Child Health, The Aga Khan University, Karachi, Pakistan.
Curr Probl Pediatr Adolesc Health Care. 2010 Feb;40(2):20-35. doi: 10.1016/j.cppeds.2009.12.004.