Affiliation: | (1) Department of Mathematics, University of Kalyani, PO Kalyani, 741 235 Dist. Nadia, India;(2) Present address: Indian Institute of Mechanics of Continua, c/o Dr. Pran Ranjan Sengupta, India;(3) Present address: 201, Manicktala Main Road, Suite No. 42, 700 054 Calcutta, India |