In this paper, we establish Hermite-Hadamard type inequalities for Riemann-Liouville fractional integrals via strongly h-convex functions. Some midpoint type and trapezoid type estimates related to them for n-times differentiable functions are also obtained, which extend some known results.

In this note, we show that the Hausdorff operator $H_{\Phi}$ is unbounded on a large family of Quasi-Banach spaces, unless $H_{\Phi}$ is a zero operator.