Perturbation Ideals and Fredholm Theory in Banach Algebras. Extracta Mathematicae, [S. l.], v. 37, n. 1, p. 91–110, 2022. DOI: 10.17398/2605-5686.37.1.91. Disponível em: https://revista-em.unex.es/index.php/EM/article/view/2605-5686.37.1.91.. Acesso em: 19 may. 2024.