ANSARI-PIRI, E.; SABET, M. THE NUMERICAL RANGE OF AN ELEMENT OF A CLASS OF TOPOLOGICAL ALGEBRAS. Italian Journal of Pure and Applied Mathematics, [S. l.], v. 41, p. 58–64, 2019. Disponível em: https://journals.uniurb.it/index.php/ijpam/article/view/7153. Acesso em: 27 oct. 2026.