Usman, Usman. “Comparison Analysis Of Optimal Portfolio With The Capital Asset Pricing Model (CAPM) Before And During The Covid-19 Pandemic : Study on Liquid-45 Index Stock Period 2018-2021”. AJIRSS: Asian Journal of Innovative Research in Social Science 1, no. 3 (August 6, 2022): 89–97. Accessed April 21, 2026. https://www.das-institute.com/journal/index.php/ajirss/article/view/157.