CASTILLO, R. E.; SULTAN, B. A derivative-type operator and its application to the solvability of a nonlinear three point boundary value problem. CUBO, A Mathematical Journal, [S. l.], v. 24, n. 3, p. 521–539, 2022. DOI: 10.56754/0719-0646.2403.0521. Disponível em: https://cubo.ufro.cl/ojs/index.php/cubo/article/view/3213. Acesso em: 23 apr. 2024.