1. Department of Mathematics University of Peshawar Peshawar 25000 Pakistan
2. Department of Computing, Mathematics and Electronics “1 Decembrie 1918” University of Alba Iulia Alba Iulia 510009 Romania
3. Faculty of Mathematics and Computer Science Transilvania University of Brasov Iuliu Maniu Street 50 Brasov 500091 Romania
4. Faculty of Science and Arts Mohail Asser, King Khalid University Abha Saudi Arabia