H. V. DEDANIA; A. B. PATEL. Spatial Numerical Range in Non-unital, Normed Algebras II. International Journal of Mathematics And its Applications, [S. l.], v. 10, n. 2, p. 1–4, 2022. Disponível em: http://ijmaa.in/index.php/ijmaa/article/view/1. Acesso em: 17 may. 2024.