**About the Editor**

**Radu Precup**, Professor, received his Ph.D. degree in Mathematics from Babes¸-Bolyai Unversity of Cluj-Napoca, Romania, in 1985 and held a postdoctoral BGF fellowship at Paris 6 University between October 1990 and June 1991. He is currently Full Professor in the Department of Mathematics at Babes¸-Bolyai University. Dr. Precup's research interests include nonlinear functional analysis, nonlinear ordinary and partial differential equations, and biomathematics. He authored over 150 research papers and the books Methods in Nonlinear Integral Equations (2002, Springer), Theorems of Leray-Schauder Type and Applications (with D. O'Regan, 2001, CRC), Linear and Semilinear Partial Differential Equations (2013, De Gruyter), and Ordinary Differential Equations (2018, De Gruyter).
