1. Mathematics Department, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
2. Institute for Mathematical Research, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
3. College of Foundation and General Studies, Universiti Tenaga Nasional, 43000 Kajang, Selangor, Malaysia
4. Faculty of Science and Technology, Universiti Sains Islam Malaysia (USIM), 71800 Negeri Sembilan, Malaysia