BENCHOHRA, M. et al. 2018. Existence and stability results for nonlocal initial value problems for differential equations with Hilfer fractional derivative. Studia Universitatis Babeș-Bolyai Mathematica. 63, 4 (Dec. 2018), 447–464. DOI:https://doi.org/10.24193/subbmath.2018.4.03.