Fitriyani, Dhea Eka. “Analysis of the Markowitz Method and the Single Index Method in Determining the Optimal Portfolio”. Almana : Jurnal Manajemen dan Bisnis 5, no. 1 (April 24, 2021): 126–133. Accessed December 25, 2025. https://journalfeb.unla.ac.id/index.php/almana/article/view/1592.