M. Sabir A, أحمد. The Numerical Range of 6 Χ 6 Irreducible Matrices. RJCSM [Internet]. 2025 Jun. 25 [cited 2025 Aug. 3];4(2):89-98. Available from: https://rjps.uomosul.edu.iq/index.php/csmj/article/view/19642