1. School of Mathematical Sciences, Universiti Sains Malaysia, Minden, Penang, Malaysia
2. School of Management, Universiti Sains Malaysia, Minden, Penang, Malaysia
3. Faculty of Engineering, Computing and Science, Swinburne University of Technology Sarawak Campus, Kuching, Sarawak, Malaysia
4. Department of Mathematics, International University of Business Agriculture and Technology, Dhaka, Bangladesh