**About the Editor**

**Sotiris K. Ntouyas** is Professor Emeritus in the Department of Mathematics of the University of Ioannina, Greece. He received his BS degree and PhD from the University of Ioannina, in 1972 and 1980, respectively. His research interests include initial and boundary value problems for differential equations (ordinary, functional, with deviating arguments, neutral, partial, integrodifferential, inclusions, impulsive, fuzzy, stochastic, fractional), inequalities, asymptotic behavior and controllability. More than 640 of his papers have appeared in print or have been accepted for publication in refereed journals. He is the co-author of the books *Impulsive differential equations and inclusions, Controllabibility for semilinear functional differential equations and inclusions, Quantum Calculus: New Concepts, Impulsive IVPs and BVPs, Inequalities and Hadamard-Type Fractional Differential Equations, Inclusions and Inequalities*. He is a member of 21 international journals' Editorial Boards, and a reviewer for many international journals. He appears in the 2018 list, published by Clarivate Analytics, of Highly Cited Researchers.
