1. a DLR German Aerospace Research Establishment Institute for Radio Frequency Technology D-8031 Wessling/Oberpfaffenhofen Federal Republic of Germany
2. b DLR German Aerospace Research Establishment Institute for Radio Frequency Technology D-8031 Wessling/Oberpfaffenhofen Federal Republic of Germany
3. c DLR German Aerospace Research Establishment Institute for Radio Frequency Technology D-8031 Wessling/Oberpfaffenhofen Federal Republic of Germany