DE FIGUEIREDO, D. G. An Invitation to Semilinear Elliptic Equations. CUBO, A Mathematical Journal, [S. l.], v. 5, n. 2, p. 159–183, 2003. Disponível em: https://cubo.ufro.cl/ojs/index.php/cubo/article/view/1694. Acesso em: 19 may. 2024.