Ali El Mfadel, Said Melliani, M’hamed Elomari. New existence results for nonlinear functional hybrid differential equations involving the ψ−Caputo fractional derivative. Results in Nonlinear Analysis [Internet]. 2022 Nov. 7 [cited 2025 May 6];5(1):78-86. Available from: https://www.nonlinear-analysis.com/index.php/pub/article/view/87