[1] MAX PLANCK INST EXTRATERR PHYS,D-85740 GARCHING,GERMANY
[2] SRON,NL-3584 CA UTRECHT,NETHERLANDS
[3] UNIV NEW HAMPSHIRE,CTR SPACE SCI,DURHAM,NH 03857
[4] CNR,IFCAI,I-90139 PALERMO,ITALY
[5] USN,RES LAB,WASHINGTON,DC 20375
[6] NORTHWESTERN UNIV,DEPT PHYS & ASTRON,EVANSTON,IL 60208
[7] UNIV SPACE RES ASSOCIATES,WASHINGTON,DC 20375
[8] STANFORD UNIV,HANSEN EXPT PHYS LAB,STANFORD,CA 94305
[9] NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771
[10] NASA,GEORGE C MARSHALL SPACE FLIGHT CTR ES84,HUNTSVILLE,AL 35812
[11] UNIV ALABAMA,DEPT PHYS,HUNTSVILLE,AL 35899