Guerfi, A., and A. Ardjouni. “Existence, Uniqueness, Continuous Dependence and Ulam Stability of Mild Solutions for an Iterative Fractional Differential Equation”. CUBO, A Mathematical Journal, vol. 24, no. 1, Apr. 2022, pp. 83–94, doi:10.4067/S0719-06462022000100083.