YANG, Y. ON EXTREME POINTS OF THE JOINT NUMERICAL RANGE. Tamkang Journal of Mathematics, [S. l.], v. 21, n. 4, p. 399–403, 1990. DOI: 10.5556/j.tkjm.21.1990.4689. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/4689. Acesso em: 2 may. 2024.