GUO, X.; LIU, G. Existence of positive solutions for the boundary value problem of a nonlinear fractional differential equation. JOURNAL OF ADVANCES IN MATHEMATICS, [S. l.], v. 10, n. 9, p. 3862–3875, 2015. DOI: 10.24297/jam.v10i9.1897. Disponível em: https://rajpub.com/index.php/jam/article/view/1897. Acesso em: 17 may. 2024.