1. Department of Mathematics, College of Science, Northern Border University, Arar 73213, Saudi Arabia
2. Department of Mathematics and Computer Science, Transilvania University of Brasov, 500036 Brasov, Romania
3. Department of Computing, Mathematics and Electronics, “1 Decembrie 1918” University of Alba Iulia, 510009 Alba Iulia, Romania
4. Department of Mathematics, Technical University of Cluj-Napoca, 400114 Cluj-Napoca, Romania