[1] Govt Coll Univ Faisalabad, Dept Math, Faisalabad, Pakistan
[2] King Abdulaziz Univ, Fac Sci, Dept Math, Jeddah 21521, Saudi Arabia
[3] China Med Univ, China Med Univ Hosp, Dept Med Res, Taichung, Taiwan
[4] Lamar Univ, Mech Engn Dept, Beaumont, TX 77710 USA