1. Department of Mathematics, Amity University Maharashtra, Mumbai, Maharashtra 410206, India
2. Department of Mathematics, Bankura University, West Bengal 722155, India
3. Department of Mathematics, Iowa State University, Ames, IA 50011, USA
4. Laboratoire d’Analyse Nonlinéaire et Mathématiques Appliquées, University of Tlemcen, Tlemcen 13000, Algeria
5. Biomathematics Laboratory, Université Sidi Bel-Abbes, P.B. 89, 22000, Algeria
6. Agricultural and Ecological Research Unit, Indian Statistical Institute, 203, B. T. Road, Kolkata 700108, India