1. Department of Mathematics College of Science Qassim University Buraydah Saudi Arabia
2. Faculty of Science, Department of Mathematics Tanta University Tanta Egypt
3. Department of Mathematics Yusuf Maitama Sule University Kano Nigeria
4. School of Mathematics and Statistics Central South University Changsha China
5. Faculty of Economics Eötvös Loránd University Budapest Hungary
6. Department of Mathematics Guangdong University of Petrochemical Technology Maoming China
7. Faculty of Physical Sciences, Department of Mathematical Sciences Bayero University Kano Nigeria