FEČKAN, M.; POSPÍŠIL, M. On equations with generalized periodic right-hand side. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 70, n. 2, p. 255–279, 2018. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/1555. Acesso em: 11 apr. 2025.