Institution: | (1) Free University, Amsterdam, The Netherlands;(2) Astronomical Institute, Bratislava, Czechoslovakia;(3) National Aerospace Laboratory NLR, Amsterdam;(4) Sterrewacht Sonnenborgh, Utrecht, The Netherlands;(5) Eötvös University, Budapest;(6) SSD, ESTEC, Noordwijk;(7) Sterrewacht, Leiden |