Malki, Z., F. Berhoun, and A. Ouahab. “System of Boundary Random Fractional Differential Equations via Hadamard Derivative”. Annales Universitatis Paedagogicae Cracoviensis Studia Mathematica, vol. 20, Apr. 2021, pp. 17-41, https://studmath.uken.krakow.pl/article/view/8265.