Stojan Radenovic has the position of Full Professor at the Faculty of Mechanical Engineering, University of Belgrade in Serbia. He is a referee for several journals: Kragujevac Journal of Mathematics, Matematicki Vesnik, Applied Mathematics Letters, Computers and Mathematics with Applications, Nonlinear Analysis, Fixed-Point Theory and Applications, Fixed-Point Theory, Journal of Applied Mathematics, and others. His research interests are functional analysis, especially the theory of locally convex spaces and nonlinear analysis, and especially the theory of fixed points in abstract metric spaces and metric spaces. He has published a large number of papers in many famous journals of the mathematical and engineering sciences.