HEIKKILA, S. Fixed Point Results for Set-Valued and Single-Valued Mappings in Ordered Spaces. CUBO, A Mathematical Journal, [S. l.], v. 10, n. 4, p. 119–135, 2008. Disponível em: https://cubo.ufro.cl/ojs/index.php/cubo/article/view/1493. Acesso em: 20 apr. 2024.