1. School of Distance Education, Universiti Sains Malaysia, Penang, Malaysia;
2. School of Chemical Sciences, Universiti Sains Malaysia, Penang, Malaysia;
3. Cluster of Integrative Medicine, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Penang, Malaysia;
4. Universiti Kuala Lumpur, Malaysian Institute of Chemical and Bioengineering Technology, Melaka, Malaysia;
5. Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, Perak, Malaysia