[1] Univ Engn & Technol, Dept Basic Sci, Taxila, Pakistan
[2] COMSATS Univ Islamabad, Dept Math, Wah Campus, Wah Cantt, Pakistan
[3] Int Telemat Univ Uninettuno, Sect Math, Rome, Italy
[4] King Saud Univ Riyadh, Coll Sci, Dept Phys & Astron, King, WI, Saudi Arabia
[5] King Saud Univ, Ind Engn Dept, Coll Engn, Riyadh, Saudi Arabia