Svetlin G. Georgiev (born 1974, Bulgaria) has worked in various areas of mathematics. His current focus: harmonic analysis, functional analysis, partial differential equations, ordinary differential equations, Clifford and quaternion analysis, integral equations, dynamic calculus on time scales. Inci M. Erhan (born 1971, Bulgaria) is a full professor of mathematics at Atilim University, Turkey. Her areas of research include numerical solutions of differential equations and dynamic equations on time scales, fixed point theory and its applications.