1. Department of Mathematics, National Institute of Technology Manipur, Langol, Imphal 795004, India
2. Department of Mathematics, Manipur University, Canchipur, Imphal 795003, India
3. Department of Mathematics, University of Management and Technology, Lahore 54770, Pakistan
4. Department of Mathematics and Applied Mathematics, Sefako Makgatho Health Sciences University, Medunsa, Pretoria 0204, South Africa
5. Department of Basic Sciences, Deanship of Preparatory Year, King Faisal University Al Ahsa, Al Hofuf 31982, Saudi Arabia