1. School of Information Science and Technology, Yunnan Normal University, Yunnan, P. R. China
2. Department of Mathematics, CHRIST, (Deemed to be University) Bengaluru 560029, India
3. Department of Mathematics, Faculty of Science, Davangere University, Shivagangothri, Davangere 577007, India
4. Department of Mathematics and Science Education, Faculty of Education, Harran University Sanliurfa, Turkey