ELOE, Paul W.; NEUGEBAUER, Jeffrey T. Maximum, anti-maximum principles and monotone methods for boundary value problems for Riemann-Liouville fractional differential equations in neighborhoods of simple eigenvalues. CUBO, A Mathematical Journal, [S. l.], p. 251–272, 2023. DOI: 10.56754/0719-0646.2502.251. Disponível em: https://cubo.ufro.cl/index.php/cubo/article/view/3446. Acesso em: 7 mar. 2026.