Y. Guo, “Solvability of boundary-value problems for nonlinear fractional differential equations”, Ukr. Mat. Zhurn., vol. 62, no. 9, pp. 1211–1219, Sep. 2010, Accessed: Feb. 16, 2026. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/2949