MugbilA. “Nonexistence Results for a System of Nonlinear Fractional Integro-Differential Equations”. Ukrains’kyi Matematychnyi Zhurnal 75, no. 4 (May 10, 2023): 478 - 490. Accessed November 21, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/6902.