Liu SY, Trope GE, Buys YM, El-Defrawy SR, Khan AM, Jin YP. Visual impairment and the Ontario disability support program. Can J Ophthalmol. 2020 Jun;55(3):212-20. doi: 10.1016/j.jcjo.2019.12.009
Cropper ML, Haile M, Lampietti J, Poulos C, Whittington D. The demand for a malaria vaccine: evidence from Ethiopia. J Dev Econ. 2004 Oct 1;75(1):303-18.