المؤلفون: Singh, Raju Jan, Bodea, Cristina, Higashijima, Masaaki
URL الوصول: http://elibrary.worldbank.org/doi/pdf/10.1596/1813-9450-7681http://elibrary.worldbank.org/doi/abs/10.1596/1813-9450-7681
URL الوصول: http://elibrary.worldbank.org/doi/pdf/10.1596/1813-9450-7100http://elibrary.worldbank.org/doi/abs/10.1596/1813-9450-7100