DOWNEY, L.; ONG, B. W. Extremal Vectors for a Class of Operators. Sarajevo Journal of Mathematics, [S. l.], v. 4, n. 2, p. 259–268, 2024. DOI: 10.5644/SJM.04.2.11. Disponível em: https://sjm.anubih.ba/index.php/sjm/article/view/369. Acesso em: 15 oct. 2024.