1. Gandhi Smarak PG College, Samodhpur, Jaunpur-223102, U.P., India
2. Department of Mathematics, Central University of Rajasthan, Bandarsindri, Kishangarh 305801, Ajmer, Rajasthan, India
3. Department of Mathematics and SRM Research Institute, SRM University, Kattankulathur-603 203, Tamil Nadu, India
4. Department of Mathematics, B.I.T., Sindri, Dhanbad-828123, India
5. Department of Mathematics and Computing, Indian Institute of Technology (ISM), Dhanbad 826004, India