Faisal, F. I., Ruma, Z., Anwar, Budiyanti, H. and Natsir, U. D. (2023) “Optimal Portfolio Formation With Single Index Method: Study on Stocks Listed in the IDX High Dividend 20 Index on the Indonesia Stock Exchange for Period 2019-2022”, Economics and Business Journal (ECBIS), 1(5), pp. 569–578. doi: 10.47353/ecbis.v1i5.62.