RAZZAGHI, M.; MARZBAN, H.-R. Hybrid Functions in the Calculus of Variations. CUBO, A Mathematical Journal, [S. l.], v. 4, n. 1, p. 293–313, 2002. Disponível em: https://cubo.ufro.cl/ojs/index.php/cubo/article/view/1735. Acesso em: 20 may. 2024.