AKPANIBAH, E. .; AZOR†, P. . Analysis of investment portfolio with 2 × 2 positive definite matrix and mortality risk under exponential utility. International Journal of Mathematical Analysis and Modelling, [S. l.], v. 6, n. 2, 2023. Disponível em: http://tnsmb.org/journal/index.php/ijmam/article/view/117. Acesso em: 25 aug. 2026.