[1] Senior Research Scholar, Department of Mathematics, Indian Institute of Technology Roorkee, Roorkee - 247667, Uttarakhand, India
[2] Indian Institute of Technology Roorkee, Roorkee-247667, Uttarakhand, India
[3] Department of Mathematics, Indian Institute of Technology Roorkee, India
[4] Indian Institute of Technology Roorkee, Roorkee - 247667, Uttarakhand, India
[5] Department of Mathematics, Sant Longowal Institute, Engineering and Technology Longowal, Punjab, India