[1] UNIV MANCHESTER,NUFFIELD RADIO ASTRON LABS,MACCLESFIELD SK11 9DL,ENGLAND
[2] PRINCETON UNIV,JOSEPH HENRY LABS,PRINCETON,NJ 08544
[3] PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544
[4] CAAST,CTR ASTRON & ASTROPHYS,BEIJING,PEOPLES R CHINA
[5] BEIJING UNIV,DEPT GEOPHYS,BEIJING 100871,PEOPLES R CHINA
[6] UNIV PALERMO,IST FIS,I-90134 PALERMO,ITALY
[7] CNR,IST RADIOASTRON,I-40126 BOLOGNA,ITALY