مروة عبد الستار جبار, 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. IJAS [Internet]. 2024 Jul. 1 [cited 2025 Jan. 7];17(70):25-51. Available from: https://mail.journals.uokerbala.edu.iq/index.php/ijas/article/view/1888