Brahim Tellab. Positivity results on the solutions for nonlinear two-term boundary value problem involving the ψ-Caputo fractional derivative. J. Math. Anal. Model. [Internet]. 2022 Dec. 30 [cited 2026 Apr. 19];3(3):14-30. Available from: https://sabapub.com/index.php/jmam/article/view/523