Rahayu W, Hariyanto W. Analysis of Portfolio Expected Returns as a Material Consideration for Investors in Choosing Investments in the Pandemic Period (Formation of Optimal Portfolios Using the Black Litterman Model on Hang Seng Stocks for the 2017-2019 Period). acopen [Internet]. 2021Dec.31 [cited 2024Apr.18];50:10.21070/acopen.5.2021.2149. Available from: https://acopen.umsida.ac.id/index.php/acopen/article/view/2149