M. SABIR, A. The Numerical Range of 6 Χ 6 Irreducible Matrices. AL-Rafidain Journal of Computer Sciences and Mathematics, [S. l.], v. 4, n. 2, p. 89–98, 2007. DOI: 10.33899/csmj.2007.164018 . Disponível em: https://csmj.uomosul.edu.iq/index.php/csmj/article/view/36679. Acesso em: 17 dec. 2025.