1. The Launch Loop;Lofstrom;AIAA Paper,1985
2. The orbital tower: a spacecraft launcher using the Earth’s rotational energy;Pearson;Acta Astronaut.,1975
3. Space elevator stage I;Knapman;62nd International Astronautical Congress, Cape Town, South Africa,2011
4. High stage one;Knapman;Space Elevator Conference,2012