[IEEE DIPED - 2000. Proceedings of 5th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory - Tbilisi, Georgia, USA (2000.10.3-2000.10.6)] DIPED - 2000. Proceedings of 5th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory (IEEE Cat. No.00TH8508) - Convergence of iterative method for problem with free phase in case of isometric operator