Manurung, Adler Haymans, Nera Marinda Machdar, Jadongan Sijabat, and Amran Manurung. “The Construction of a Portfolio Using Varying Methods and the Effects of Variables on Portfolio Return”. International Journal of Economics and Financial Issues 14, no. 1 (January 20, 2024): 233–241. Accessed November 14, 2024. https://econjournals.com./index.php/ijefi/article/view/15314.