Report of the Task Force on potentially hazardous Near Earth Objects, p49, Department of Trade and Industry (UK), September 2000, Pub 4990/5k/9/00/NP.URN00/1041, retrieved online, 16 May 2009. [وصلة مكسورة]نسخة محفوظة 2009-02-19 في Wayback Machine
web.archive.org
Report of the Task Force on potentially hazardous Near Earth Objects, p49, Department of Trade and Industry (UK), September 2000, Pub 4990/5k/9/00/NP.URN00/1041, retrieved online, 16 May 2009. [وصلة مكسورة]نسخة محفوظة 2009-02-19 في Wayback Machine