“…As a result, some well-known integral inequalities by the approach of fractional calculus have been carried out by many authors, including Chen [4] and Mohammed [23] in the study of the Hermite-Hadamard inequality, and Set et al [29] in the Simpson type integral inequality for Riemann-Liouville fractional integrals, Chen and Katugampola [5] in the Hermite-Hadamard-Fejér type inequality for Katugampola fractional integrals, Wang et al [33] in the Ostrowski type inequality for Hadamard fractional integrals, Du et al [8] in the extensions of trapezium inequalities for k-fractional integrals, and Khan et al [14] in the Hermite-Hadamard inequality for conformable fractional integrals. For more results related to the fractional integral operators, the interested reader is directed to [1,11,13,16,17,21,25,28,30] and the references cited therein.…”