1. Department of Mathematics, AMET Deemed to be University, Chennai 603112, Tamil Nadu, India
2. School of Industrial Engineering, Pontificia Universidad Católica de Valparaíso, Valparaíso 2362807, Chile
3. Department of Mathematics, Sri Eshwar College of Engineering, Coimbatore 641202, Tamil Nadu, India
4. Centre of Mathematics, Universidade do Minho, 4710-057 Braga, Portugal