Institution: | (1) Fachbereich Mathematik, Technische Universität, PSF 964, D-09009 Chemnitz, Germany;(2) Hydroacoustic Department Marine Hydrophysical Institute, Ukrainian Academy of Sciences, Street of the Soviet Army 3, 270100 Odessa, Ukraine;(3) Department of Mathematics, College of William and Mary, 23187 Williamsburg, VA, USA |