Affiliation: | Technische Universit?t Chemnitz, Fakult?t für Mathematik, D-09107 Chemnitz, Germany.?e-mail: aboettch@mathematik.tu-chemnitz.de, DE Ukrainian Academy of Sciences, Marine Hydrophysical Institute,?Hydroacoustic Department, Preobrazhenskaya Street 3, 270 100 Odessa, Ukraine.?e-mail: karlik@imem.odessa.ua}, UA Rostov-on-Don State University, Faculty of Mechanics and Mathematics, Bolshaya Sa‐dovaya Street 105, 344 711 Rostov-on-Don, Russia.?e-mail: rabinov@ns.unird.ac.ru}, RU
|