[1] UNIV LEICESTER,DEPT PHYS,X-RAY ASTRON GRP,LEICESTER LE1 7RH,ENGLAND
[2] UNIV FLORIDA,ROSEMARY HILL OBSERV,DEPT ASTRON,GAINESVILLE,FL 32611
[3] UNIV MICHIGAN,RADIO ASTRON OBSERV,DEPT ASTON,ANN ARBOR,MI 48109
[4] UNIV CALIF SANTA CRUZ,LICK OBSERV,MT HAMILTON,CA 95140
[5] UNIV MASSACHUSETTS,DEPT PHYS & ASTRON,AMHERST,MA 01003
[6] CALTECH,PALOMAR OBSERV,DIV PHYS MATH & ASTRON,PASADENA,CA 91125
[7] UNIV ARIZONA,STEWARD OBSERV,TUCSON,AZ 85724
[8] NATL RADIO ASTRON OBSERV,CHARLOTTESVILLE,VA 22901