BRAHIM TELLAB. Positivity results on the solutions for nonlinear two-term boundary value problem involving the ψ-Caputo fractional derivative. Journal of Mathematical Analysis and Modeling, [S. l.], v. 3, n. 3, p. 14–30, 2022. DOI: 10.48185/jmam.v3i2.523. Disponível em: https://www.sabapub.com/index.php/jmam/article/view/523. Acesso em: 25 may. 2026.