Karima Mebarki is a professor in the Department of Mathematics, Bejaia University, Algeria. Her research interests are: fixed point theory, fixed point index theory, nonlinear ordinary differential equations, and boundary value problems. Svetlin G. Georgiev is a mathematician who has worked in various aspects of mathematics. Currently, he focuses on harmonic analysis, ordinary differential equations, partial differential equations, time scale calculus, integral equations, and nonlinear analysis. He has published several books with Taylor & Francis/CRC Press. Smail Djebali works on fixed point theory and applications in differential equations. He is currently a professor at Imam Mohammad Ibn Saud Islamic University, Riyadh, Saudi Arabia, Khaled Zennir earned his PhD in mathematics in 2013 from Sidi Bel Abbès University, Algeria. In 2015, he received his highest diploma in Habilitation in mathematics from Constantine University, Algeria. He is currently an assistant professor at Qassim University in the Kingdom of Saudi Arabia. His research interests lie in the subjects of nonlinear hyperbolic partial differential equations: global existence, blowup, and long time behavior.