1. Faculty of Business and Accountancy, Department of Operations and Management Information Systems, Universiti Malaya, Kuala Lumpur, Malaysia
2. School of Mathematical Sciences, Universiti Sains Malaysia, Penang, Malaysia
3. Faculty of Science, Institute of Mathematical Sciences, Universiti Malaya, Kuala Lumpur, Malaysia
4. Faculty of Science, Department of Physical and Mathematical Sciences, Universiti Tunku Abdul Rahman, Perak, Malaysia