GORBACHUK, V. I.; GORBACHUK, M. L. The Dirichlet problem for differential equations in a Banach space. Methods of Functional Analysis and Topology, [S. l.], v. 18, n. 2, p. 140–151, 2012. Disponível em: https://zen.imath.kiev.ua/index.php/mfat/article/view/510. Acesso em: 18 dec. 2025.