Alkhathlan, K. A., T. T. Y. Alkhateeb, H. Mahmood, and W. A. Bindabel. “Determinants of Diversification from Oil Sector in Saudi Arabia”. International Journal of Energy Economics and Policy, vol. 10, no. 5, Aug. 2020, pp. 384-91, https://www.econjournals.com/index.php/ijeep/article/view/9709.