[1] Univ Malaya, Inst Math Sci, Fac Sci, Kuala Lumpur 50603, Malaysia
[2] Casablanca Hassan II Univ, Fac Sci Ben Msik, Quantum Phys & Magnetism Team, LPMC, Casablanca, Morocco
[3] Univ Tunku Abdul Rahman, Dept Math & Actuarial Sci, Jalan Sungai Long, Cheras 43000, Malaysia