[Zhou, Shuang-Shuang] Hunan City Univ, Sch Sci, Yiyang 413000, Peoples R China.
[Rashid, Saima] Govt Coll Univ Faisalabad, Dept Math, Faisalabad, Pakistan.
[Noor, Muhammad Aslam; Noor, Khalida Inayat] COMSATS Univ, Dept Math, Islamabad, Pakistan.
[Safdar, Farhat] SBK Women Univ, Dept Math, Quetta, Pakistan.
[Chu, Yu-Ming] Huzhou Univ, Dept Math, Huzhou 313000, Peoples R China.