1. Associate Professor, Faculty of Mathematical and Statistical Sciences, Institute of Natural Sciences and Humanities, Shri Ramswaroop Memorial Univ., Lucknow-Deva Rd., Barabanki, Uttar Pradesh 225003, India (corresponding author).
2. Assistant Professor, Dept. of Mathematics and Computer Science, School of Basic Sciences, Babu Banarasi Das Univ., Lucknow, Uttar Pradesh 226028, India.
3. Retired, 2A/T10-801, Mandakini Enclave, Avadh Vihar Yojna, Lucknow, Uttar Pradesh 226002, India; formerly, Professor, Mathematics Dept., Banaras Hindu Univ., Varanasi, Uttar Pradesh 221005, India.