[1] Abdul Wali Khan Univ Mardan, Dept Math, Mardan 23200, Pakistan
[2] Umm Al Qura Univ, Dept Math Deanship Appl Sci, Mecca 24231, Saudi Arabia
[3] Univ Malaysia Terengganu, Fac Ocean Engn Technol & Informat, Programme Math, Kuala Nerus 21030, Terengganu, Malaysia
[4] Univ Punjab, Dept Math, Lahore 54590, Pakistan