“(Estimation and Analysis of the Cobb-Duglas Production Function for the Rail Transport Sector in Iraq for the Period 1990-2016 Using the ARDL Model)”. Journal of Economics and Administrative Sciences 24, no. 109 (December 1, 2018): 358. Accessed April 29, 2024. https://jeasiq.uobaghdad.edu.iq/index.php/JEASIQ/article/view/1553.