[1] Air Univ, Dept Math, Islamabad, Pakistan
[2] Cent South Univ, Sch Math & Stat, Changsha, Peoples R China
[3] Capital Univ Sci & Technol CUST, Dept Math, Islamabad, Pakistan
[4] New Valley Univ, Fac Sci, Dept Math, Al Wadi Al Gadid, Egypt
[5] Northern Border Univ, Coll Business Adm, Finance & Insurance Dept, Ar Ar, Saudi Arabia
[6] Northern Border Univ, Coll Business Adm, Finance & Insurance Dept, Ar Ar 1321, Saudi Arabia