1. Department of Mathematics, Institute of Science, Banaras Hindu University, Varanasi, India
2. Department of Mathematics, College of Arts and Sciences, Prince Sattam bin Abdulaziz University, Wadi Aldawaser, Saudi Arabia
3. Faculty of Engineering, Kuwait College of Science and Technology, Doha District, Kuwait
4. Department of Mathematical and Physical Sciences, University of Nizwa, Birkat Al Mawz, Oman