1. Department of Mathematics, College of Science, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
2. Department of Mathematics, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, China
3. Department of Mathematics, University of Malakand, Chakdara Dir(L), 18000 Khyber Pakhtunkhwa, Pakistan
4. Department of Mathematics and General Sciences, Prince Sultan University, Riyadh, Saudi Arabia