[1] NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA
[2] EUROPEAN SPACE RES ORG, DIV ASTRON, NOORDWIJK, NETHERLANDS
[3] UCL, LONDON WC1E 6BT, ENGLAND
[4] UNIV COLORADO, BOULDER, CO 80302 USA
[5] EUROPEAN SPACE AGCY, SATELLITE TRACKING STN, MADRID, SPAIN
[6] OHIO STATE UNIV, DEPT ASTRON, COLUMBUS, OH 43210 USA
[7] SRC, APPLETON LAB, SLOUGH, BERKSHIRE, ENGLAND
[8] OSSERVATORIO ASTROFIS, CATANIA, ITALY
[9] DEPT THEORET PHYS, OXFORD, ENGLAND
[10] HARVARD UNIV, SMITHSONIAN CTR ASTROPHYS, CAMBRIDGE, MA 02138 USA