Astronomical Institute, Bratislava, Czechoslovakia
Ľ. Kresák
Space Research Institute, Moscow, Russia
V. I. Moroz & I. D. Novikov
Observatoire de Paris, Paris, France
Suzanne Débarbat
Max Planck Institute for Aeronomy, Katlenburg-Lindau
W. I. Axford
Radioastronomie ENS, Paris
P. Boissé
Laboratory for Space Research, Utrecht, The Netherlands
Cornelis de Jager
Observatory Sonnenborgh, Utrecht
H. Nieuwenhuijzen
Faculty of Aerospace Engineering, Delft University of Technology, Delft, The Netherlands
K. F. Wakker
Leiden Observatory, The Netherlands
C. J. van Houten
The Astronomical Institute, Utrecht, The Netherlands
H. Nieuwenhuijzen & J. R. W. Heintze
Mount Stromlo and Siding Spring Observatories at Canberra, Canberra, Australia
M. A. Dopita
Space Research Laboratory, Utrecht, The Netherlands
K. A. van der Hucht
Herzberg Institute, Victoria, Canada
Sidney van den Bergh