المؤلفون: Reimer, Jeffrey J., Hertel, Thomas W.
URL الوصول: http://elibrary.worldbank.org/doi/pdf/10.1596/1813-9450-3444http://elibrary.worldbank.org/doi/abs/10.1596/1813-9450-3444
المؤلفون: Reimer, Jeffrey J.
URL الوصول: http://elibrary.worldbank.org/doi/pdf/10.1596/1813-9450-2790http://elibrary.worldbank.org/doi/abs/10.1596/1813-9450-2790