1. Azpeitia, A.G.: Convex functions and the Hadamard inequality. Rev. Colomb. Math. 28, 7–12 (1994)
2. Ali, A., Gulshan, G., Hussain, R., Latif, A., Muddassar, M.: Generalized inequalities of the type of Hermite–Hadamard–Fejer with quasi-convex functions by way of $$\mathit{k}$$ k -fractional derivatives. J. Comput. Anal. Appl. 22(7), 1208–1219 (2017)
3. Bakula, M.K., Pečarić, J.: Note on some Hadamard-type inequalities. J. Inequal. Pure Appl. Math. 5(3), 74 (2004)
4. Bombardelli, M., Varosanec, S.: Properties of h-convex functions related to the Hermite–Hadamard–Fejer inequalities. Comput. Math. Appl. 58, 1869–1877 (2009)
5. Budak, H., Sarikaya, M.Z.: Hermite–Hadamard type inequalities for s-convex mappings via fractional integrals of a function with respect to another function. Fasc. Math. 27, 25–36 (2016)