1. R. U. Gobithaasan:
Department of Mathematics, Faculty of Science and Technology, University Malaysia Terengganu, 21030 Kuala Terengganu, Malaysia
2. J. M. Ali:
School of Mathematical Sciences, University Sains Malaysia, 11800 Minden, Penang, Malaysia
3. Kenjiro T. Miura:
Graduate School of Science and Technology, Shizuoka University, Hamamatsu Shizuoka 432, Japan