DÍEZ, P.; PARÉS, N. .; HUERTA, A. . Accurate upper and lower error bounds by solving flux-free local problems in “stars”. European Journal of Computational Mechanics, [S. l.], v. 13, n. 5-7, p. 497–507, 2004. Disponível em: https://journals.riverpublishers.com/index.php/EJCM/article/view/2301. Acesso em: 20 jun. 2026.