“The Role of Time Gaps in Determining the Causal Relationship Between Exchange Rate and Foreign Exchange Reserve in Sudan Using Granger Causality for the Period 1980-2017”. Journal of Economic, Administrative and Legal Sciences 2, no. 11 (August 30, 2018): 107–89. Accessed July 3, 2024. https://journals.ajsrp.com/index.php/jeals/article/view/668.