On Hermite-Hadamard Inequalities for differentiable $\lambda$-preinvex   functions via Riemann-Liouville Fractional Integrals
  In this paper, we consider a new class of convex functions which is called $\lambda$-preinvex functions. We prove several Hermite-Hadamard type inequalities for differentiable $\lambda$-preinvex functions via Fractional Integrals. Some special cases are also discussed. 
Abdullah Akkurt, M. Esra Yildirim, and H\"useyin Yildirim
math.CA