-, .-., and مزاحم. “Estimating Simultaneous Equations System of the World Prices of the Grains for the Period (1961-2002)”. IRAQI JOURNAL OF STATISTICAL SCIENCES, vol. 8, no. 2, June 2025, pp. 205-22, https://rjps.uomosul.edu.iq/index.php/stats/article/view/20730.