Febrianti, W.; Sumarti, N.; Nasution, A. S.; Fitriawati, A.; Siregar, D. E. P.; S, Y. S. Optimizing ESG-Constrained Mean-Variance Portfolio Using Spiral Optimization Algorithm. J. Multidiscip. Appl. Nat. Sci. 2026, 6, 1146-1159.