مروة عبد الستار جبار, and ميثم ربيع هادي. “Solving the System of Simultaneous Equations As a Simplifying Method of Markowitz Model to Build the Optimal Stock Portfolio When Short Selling Is Allowed: Analytical Study of the Iraqi Stock Exchange”. Iraqi Journal for Administrative Sciences 17, no. 70 (July 1, 2024): 25–51. Accessed January 7, 2025. https://mail.journals.uokerbala.edu.iq/index.php/ijas/article/view/1888.