The correct authors and their affiliations should have been listed as follows:

S. Saha Ray

Lecturer,

Department of Mathematics,

B. P. Poddar Institute of Management and Technology,

137, V.I.P. Road,

Poddar Vihar,

Kolkata 700052, West Bengal, India

R. K. Bera

Heritage Institute of Technology,

Chowbaga Road,

Anandapur, Kolkata 700107, India