Mahmood, H., M. Furqan, T. T. Y. Alkhateeb, and M. M. Fawaz. “Testing the Environmental Kuznets Curve in Egypt: Role of Foreign Investment and Trade”. International Journal of Energy Economics and Policy, vol. 9, no. 2, Feb. 2019, pp. 225-8, https://econjournals.com/index.php/ijeep/article/view/7271.