المؤلفون: Gine, Xavier, Karlan, Dean, Zinman, Jonathan
URL الوصول: http://elibrary.worldbank.org/doi/pdf/10.1596/1813-9450-4985http://elibrary.worldbank.org/doi/abs/10.1596/1813-9450-4985
المؤلفون: Brigden, Linda Waverley, de Beyer, Joy
URL الوصول: http://elibrary.worldbank.org/doi/pdf/10.1596/0-8213-5402-7http://elibrary.worldbank.org/doi/abs/10.1596/0-8213-5402-7