- ^ 1.0 1.1 Greenwald, Glenn. XKeyscore: NSA tool collects 'nearly everything a user does on the internet'. The Guardian. 2013-07-31 [2023-10-15]. ISSN 0261-3077. (原始内容存档于2014-03-20) (英国英语).
- ^ Seipel, Hubert. Snowden Interview: Transcript. Norddeutscher Rundfunk: 3. January 26, 2014 [May 6, 2019]. (原始内容存档于January 28, 2014).
- ^ Greenwald, Glenn; Ackerman, Spencer. How the NSA Is Still Harvesting Your Online Data – Files Show Vast Scale of Current NSA Metadata Programs, with One Stream Alone Celebrating 'One Trillion Records Processed'. The Guardian. June 27, 2013 [August 5, 2013]. (原始内容存档于August 4, 2013).
- ^ Layne, Ken. Job Networking Site LinkedIn Filled With Secret NSA Program Names. June 18, 2013 [August 6, 2013]. (原始内容存档于December 8, 2017).
- ^ xkeyscorerules100. Panorama (ARD (broadcaster)). July 3, 2014 [July 4, 2014]. (原始内容存档于July 7, 2014).