Yahia, Y. E., L. Haiyun, M. A. Khan, S. S. H. Shah, and M. A. Islam. “The Impact of Foreign Direct Investment on Domestic Investment: Evidence from Sudan”. International Journal of Economics and Financial Issues, vol. 8, no. 6, Nov. 2018, pp. 1-10, https://www.econjournals.com/index.php/ijefi/article/view/6895.