[1] Jiangsu Univ, Sch Energy & Power Engn, Zhenjiang 212013, Peoples R China
[2] Govt Coll Univ, Dept Math, Faisalabad 38000, Pakistan
[3] Minhaj Univ, Sch Math, Lahore 54750, Pakistan
[4] King Khalid Univ, Coll Sci, Dept Math, Abha 61413, Saudi Arabia
[5] Taif Univ, Coll Sci, Dept Math, POB 11099, Taif 21944, Saudi Arabia