1. Faculty of Applied Sciences, Department of Mathematics and Informatics National University of Science and Technology Politehnica Bucharest Bucharest Romania
2. College of Science, Department of Mathematics King Saud University Riyadh Saudi Arabia
3. “Gheorghe Mihoc‐Caius Iacob” Institute of Mathematical Statistics and Applied Mathematics of the Romanian Academy Bucharest Romania
4. Faculty of Mathematics and Computer Science, Research Center in Geometry, Topology and Algebra University of Bucharest Bucharest Romania