HUSNI, Ricky Albert; SAMOSIR, Tumpal; SINDHUARTA, Siji Jati. Optimal Portfolio Comparison Based on Markowitz and Single Index Model Using IDX BUMN20 Stocks during Covid-19. Indikator: Jurnal Ilmiah Manajemen dan Bisnis, Jakarta, Indonesia, v. 6, n. 3, p. 94–104, 2022. DOI: 10.22441/indikator.v6i3.15305. Disponível em: https://training-ojs3-publikasi.mercubuana.ac.id/index.php/indikator/article/view/15305. Acesso em: 28 may. 2026.