Shah, K., and A. Ali. “Ulam-Hyers Stability Analysis to a Three-Point Boundary Value Problem for Fractional Differential Equations”. Ukrains’kyi Matematychnyi Zhurnal 72, no. 2 (February 15, 2020): 147-160. Accessed April 6, 2020. http://umj.imath.kiev.ua/index.php/umj/article/view/371.