1. Department of Mathematics, St. Thomas’ College (Autonomous), Thrissur, Kerala, India
2. University of Calicut, Malappuram, Kerala, India
3. Department of Mathematics, Sri. C. Achutha Menon Government College, Thrissur, Kerala, India
4. Marian Research Centre for Mathematics, St. Mary’s College, Thrissur, Kerala, India
5. Laboratory of Mechanics, Faculty of Sciences Aïn Chock, Hassan II University of Casablanca, Casablanca, Morocco