1. Institute of Mathematical and Physical Sciences; University of Wales; Aberystwyth; UK
2. Applied Research Laboratories; University of Texas at Austin; Austin; Texas; USA
3. NorthWest Research Associates, Inc.; Bellevue; Washington; USA
4. NorthWest Research Associates, Inc.; Tucson; Arizona; USA
5. Deutsches Zentrum für Luft und Raumfahrt; Neustrelitz; Germany
6. Department of Applied Mathematics; University of Sheffield; UK