U. . Al-qalawi, A. . AlQudah, A. A. . Alwaked, and A. A. R. . Al-Rabbaie, “The efficiency of defense-augmented production function for G20 countries: An analysis of the relationship with Country Fragile Index”, ijirss, vol. 8, no. 2, pp. 4054–4064, Apr. 2025.