1. Department of Mathematics, Hajee Mohammad Danesh Science and Technology University, Dinajpur 5200, Bangladesh
2. Department of Applied Mathematics, University of Rajshahi, Bangladesh
3. Section of Mathematics, International Telematic University Uninettuno, Corso Vittorio Emanuele II, 39, 00186 Roma, Italy
4. Department of Mathematics and Science Education, Faculty of Education, Erciyes University, Kayseri, Turkey
5. Department of Mathematics, Faculty of Science, Taif University, P. O. Box 11099, Taif 21944, Saudi Arabia