The Astronomical Institute, Utrecht
G. C. M. Reijnen, G. C. M. Reijnen, H. G. van Bueren & W. de Graaff
Laboratory for Extraterrestrial Physics-NASA/GSFC, Greenbelt, Maryland
Norman F. Ness
Jet Propulsion Laboratory, California Institute of Technology, 91103, Pasadena, Calif., USA
Arvydas J. Kliore
National Aerospace Laboratory, Amsterdam
F. J. Sonnenschein
Physics Laboratories, University of Utrecht, Utrecht, The Netherlands
A. M. Hoogenboom
Astronomical Observatory, Trieste
Margherita Hack
The University of Texas, Dallas
F. S. Johnson
Astronomical Institute, Ondrejov, Czechoslovakia
J. Kleczek
Space Research Laboratory, Utrecht
P. Hoyng
Air Force Geophysics Laboratory, Bedford, Mass.
W. Swider
Institut d'Astrophysique, Université de Liège, Cointe-Ougrée, Belgium
N. Grevesse