1. Department of Mathematics, Indian Institute of Engineering Science and Technology, Howrah, West Bengal, India
2. School of Business, Indian Institute of Technology Guwahati, North Guwahati, Assam, India
3. Department of Mathematics, Mugberia Gangadhar Mahavidyalaya, Purba Medinipur, West Bengal, India
4. Department of Mathematics, Vidyasagar University, Midnapore, West Bengal, India