Institution: | a Department of Mathematics, Bengal Engineering and Science University, Shibpur, Howrah-711103, West Bengal, Indiab Department of Mathematics, ITME, South 24 Pargana, West Bengal, 743368, Indiac Department of Mathematics, Indiana University, Bloomington, IN 47405-7106, USAd Department of Mathematics, Bengal Institute of Technology, Kolkata-700150, West Bengal, India |