1. Department of Mathematical Sciences, Faculty of Science, Universiti Teknologi Malaysia, Johor Bahru 81310, Malaysia
2. Azman Hashim International Business School, Universiti Teknologi Malaysia, Johor Bahru 81310, Malaysia
3. Department of Mathematics, Xiamen University Malaysia, Jalan Sunsuria, Bandar Sunsuria 43900, Selangor, Malaysia