FARID, Ghulam, et al. “Ostrowski-Type Fractional Integral Inequalities for Mappings Whose Derivatives Are H-Convex via Katugampola Fractional Integrals”. Studia Universitatis Babeș-Bolyai Mathematica, vol. 63, no. 4, Dec. 2018, pp. 465–474, doi:10.24193/subbmath.2018.4.04.