1. Collision frequency of artificial satellites: the creation of a debris belt;J. Geophys. Res.,1979
2. Inter-Agency Space Debris Coordination Committee: www.ladc-online.org
3. NASA Orbital Debris Program Office: orbitaldebris.jsc.gov/index.html
4. The Threat of Orbital Debris and Protecting NASA Space Assets from Satellite Collisions images.spaceref.com/news/2009/ODMediaBriefing28Apr09-1.pdf
5. Geant4 developments and applications