1. Institute for Groundwater Studies, Faculty of Natural and Agricultural Sciences, University of the Free State, South Africa
2. Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan
3. IT4Innovations, VSB-Technical University of Ostrava, 17. listopadu 2172/15, 70800, Ostrava-Poruba, Czech Republic
4. Department of Mathematics Education, Faculty of Education, Siirt University, Siirt 56100, Turkey