1. Global Market Scenario of a Space Tourist Enterprise;Abitzsch,1997
2. Space Tourism — Where are the Launchers?;Eilingsfeld,1997
3. The Design of a System for Space Tourism;Kistler,1997
4. Technical Assessment of the Minimum ‘Cost per Flight’ Potential for Space Tourism;Koelle,1997
5. The Japanese Rocket Society's Space Tourism Research;Collins,1997