المؤلفون: Akiyama, Takamasa, Baffes, John, Larson, Donald, Varangis, Panos
URL الوصول: http://elibrary.worldbank.org/doi/pdf/10.1596/0-8213-4588-5http://elibrary.worldbank.org/doi/abs/10.1596/0-8213-4588-5