1. Research Department of Mathematics, Cauvery College for Women (Affiliated to Bharathidasan University), Tiruchirappalli 620018, Tamil Nadu, India
2. Department of Mathematics, Srinivas University, Mangalore 574146, Karnataka, India
3. Department of Mathematics, Sri Eshwar College of Engineering, Coimbatore 641202, Tamil Nadu, India
4. School of Industrial Engineering, Pontificia Universidad Católica de Valparaíso, Valparaíso 2362807, Chile
5. Centre of Mathematics, Universidade do Minho, 4710-057 Braga, Portugal