1. Department of Mathematical and Physical Sciences, University of Nizwa, Nizwa, Oman
2. Department of Mathematics, Babasaheb Bhimrao Ambedkar University, Lucknow 226025, India
3. Department of Applied Sciences, National Institute of Technology Goa, Goa 403401, India
4. Department of Mathematics, Institute of Science, Banaras Hindu University, Varanasi 221005, Uttar Pradesh, India