[1] OSSERV ASTROFIS ARCETRI,I-50125 FLORENCE,ITALY
[2] LAS CAMPANAS OBSERV,PASADENA,CA 91101
[3] UNIV DELAWARE,DEPT PHYS & ASTRON,SHARP LAB,NEWARK,DE 19716
[4] CORNELL UNIV,CTR RADIOPHYS & SPACE RES,NEWMAN LAB,ITHACA,NY 14853
[5] MT WILSON OBSERV,PASADENA,CA 91101