1. School of Mathematical Sciences; Universiti Sains Malaysia; Penang Malaysia
2. Department of Operations and Management Information Systems, Faculty of Business and Accountancy; Universiti Malaya; Kuala Lumpur Malaysia
3. School of Mathematical and Computer Sciences; Heriot-Watt University Malaysia; Putrajaya Malaysia
4. Department of Physical and Mathematical Science, Faculty of Science, Universiti Tunku Abdul Rahman; Jalan Universiti; Kampar Perak Malaysia