IBRAHIM , Rabha W., Sugumaran HARIKRISHNAN, and Kuppusamy KANAGARAJAN. 2018. “Existence and Stability of Langevin Equations With Two Hilfer-Katugampola Fractional Derivatives”. Studia Universitatis Babeș-Bolyai Mathematica 63 (3):291–302. https://doi.org/10.24193/subbmath.2018.3.01.