1. Department of Mathematics, Central University of Rajasthan, NH-8 Bandarsindari, Ajmer 305817, Rajasthan, India
2. Department of Mathematics, Maharani Lal Kunwari MLK (PG) College, Balrampur 271201, Uttar Pradesh, India
3. Department of Mathematics and Computing, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, Jharkhand, India