1. Scintillation in the the Solar Wind;Coles,1993
2. Solar Tomography: deducing the three dimensional structure of the solar corona;Davila;NASA/GSFC Report,1993
3. Horizon 2000 Plus - European Space Science in the 21st Century;European Space Agency,1994
4. Horizon 2000 Plus, Assessment of Potential Cornerstones;European Space Agency - Survey Committee,1994