Prof. Dr. Nazar Dheyab Assaf, R. A. I. M. “Measuring the Role of Oil in Iraq’s Foreign Trade in Light of Price Fluctuations and Policies to Reduce Production for the Period (2004-2020)”. Design Engineering, Aug. 2021, pp. 7718-32, http://www.thedesignengineering.com/index.php/DE/article/view/3290.