Basarir H. Poor, multidimensionally speaking: evidence from South Africa. J Afr Econ. 2011 Jun 1;20(3):463-504. doi: 10.1093/jae/ejr001
Michels KB, Rothman KJ. Update on unethical use of placebos in randomised trials. Bioethics. 2003 Apr;17(2):188-204.