1. SOHO, Solar and Heliospheric Observatory, ESA Report on the Phase-A Study, SCI (85)7, by the Directorate of Scientific Programmes. (Noordwijk, December 1985).
2. CLUSTER, Study in Three Dimensions of Plasma Turbulence and Small- Scale Structure, ESA Report on the Phase-A Study, SCI (85)8, by the Directorate of Scientific Programmes. (Noordwijk, December 1985).