Formation of an optimal investment portfolio of the common stocks by using the model of simple rating – an empirical study in the Iraqi stock exchange. Journal of Al-Rafidain University College For Sciences ( Print ISSN: 1681-6870 ,Online ISSN: 2790-2293 ), [S. l.], v. 26, n. 1, p. 133–150, 2021. DOI: 10.55562/jrucs.v26i1.430. Disponível em: https://jrucs.iq/index.php/JAUCS/article/view/430. Acesso em: 16 apr. 2026.