Fadol, Hassan Tawakol A. “The Relationship Between the Gross Domestic Product, Foreign Direct Investment and Non-Oil Exports in the Saudi Economy (1970-2019)”. International Journal of Economic Development Research and Investment (IJEDRI), vol. 11, no. 1, Apr. 2020, pp. 13-25, http://icidr.org.ng/index.php/Ijedri/article/view/942.