1. “Orbital Debris Quarterly News,” NASA Orbital Debris Program Office, Vol. 19, No. 2, April 2015, http://orbitaldebris.jsc.nasa.gov/Quarterly-News/newsletter.html/.
2. “Position Paper on Space Debris Mitigation: Implementing Zero Debris Creation Zones,” ESA Paper SP-1301, International Academy of Astronautics, Paris, Oct. 2005.
3. “Process for Limiting Orbital Debris,” NASA STD-8719.14A, Washington, D.C. Dec. 2011.
4. “Active Debris Removal—An Essential Mechanism for Ensuring the Safety and Sustainability of Outer Space,” Committee on the Peaceful Uses of Outer Space, United Nations Office for Outer Space Affairs Rept. A/AC.105/C.1/2012/CRP.16, Vienna, Feb. 2012.