ZHURAVLEV, V. F. Weakly perturbed operator equations in Banach spaces. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 69, n. 6, p. 751–764, 2017. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/1733. Acesso em: 27 apr. 2025.