BELABBACI, C. The S-Jeribi essential spectrum. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 73, n. 3, p. 308–313, 2021. DOI: 10.37863/umzh.v73i3.163. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/163. Acesso em: 5 dec. 2025.