Nadia Magvira, Khusnul Khatimah, Nursan Haryanto, Sarasrina, Nur Sipa, Serli Alifia, & Suriani M. (2026). FORMATION OF AN EFFICIENT SYARIAH STOCK PORTFOLIO USING THE MARKOWITZ MODEL ON THE JAKARTA ISLAMIC INDEX. Journal Informatic, Education and Management (JIEM), 8(2), 995-1003. https://doi.org/10.61992/jiem.v8i2.453