. Abdeljabbar Ghanmi, “Existence of Positive Solutions for a Coupled System of Nonlinear Fractional Dierential Equations”, Ukr. Mat. Zhurn., vol. 71, no. 1, pp. 37–46, Jul. 2023, Accessed: Dec. 05, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/6008