RAHARJANTI, Amalia. Mean-Variance Investment Without Risk-Free Assets in PT Company Shares PT Ace Hardware (Aces.Jk), PT Mayora Indah (Myor.Jk), PT Bri (Bbri.Jk), PT Siloam Hospital (Silo.Jk), PT Eterindo Wahanatama (Etwa.Jk). Operations Research: International Conference Series, [S. l.], v. 4, n. 3, p. 105–108, 2023. DOI: 10.47194/orics.v4i3.251. Disponível em: https://www.iorajournal.org/index.php/Orics/article/view/251. Acesso em: 14 jan. 2026.