1. Balloons for Mars missions
2. G. Debouzie et R.S Kremnev. Tech. Report, CNES, GLASKOSMOS (1989).
3. D. Mège, F.X. Chaffaut, F. Costard, Ph. Masson, and J.P. Peulvast. Tech. Report n° 025, CNES (1990).
4. S.S.C. Wu, 1/15.000.000 topographic map of Mars, USGS, Flagstaff (1989).
5. F. Costard et J.P. Peulvast, Tech. Report, CNES in press (1990).