The Doughnut (English Wikipedia)

Jones, Bryony (22 June 2003). "Fresh 'doughnut' for GCHQ office". News.BBC.co.uk. BBC News. Retrieved 10 October 2021.
"MPs condemn spiraling GCHQ costs". News.BBC.co.uk. BBC News. 15 June 2004. Retrieved 17 December 2013.
"GCHQ criticised for huge move overspend". News.BBC.co.uk. BBC News. 16 July 2003. Retrieved 17 December 2013.
Savage, Mark (29 March 2010). "Inside GCHQ: 'Caution: Here comes the BBC'". News.BBC.co.uk. BBC News. Retrieved 28 December 2013.

BBC.co.uk

Whitworth, Tom (11 August 2011). "Inside the UK's top secret GCHQ base in Cheltenham". www.BBC.co.uk. BBC News. Retrieved 17 December 2013.
Knibbs, Steve (21 December 2011). "A final look at GCHQ's top secret Oakley site in Cheltenham". www.BBC.co.uk. Cheltenham, Gloucestershire: BBC News. Retrieved 11 October 2021.
"Prince Charles and Camilla visit GCHQ in Cheltenham". www.BBC.co.uk. BBC News. 3 March 2011. Retrieved 17 December 2013.
"Giant poppy made by 1,400 GCHQ intelligence agency staff". www.BBC.co.uk. BBC News. 24 October 2014. Retrieved 24 October 2014.

GCHQ.gov.uk

"Locations - Cheltenham". www.GCHQ.gov.uk. Cheltenham, Gloucestershire: GCHQ. 2021. Retrieved 11 October 2021.
"Culture - Giving back". www.GCHQ.gov.uk. Cheltenham, Gloucestershire: GCHQ. 2021. Retrieved 11 October 2021.
"Community Day 2017". www.GCHQ.gov.uk. Cheltenham, Gloucestershire: GCHQ. 8 December 2017. Retrieved 11 October 2021.

GOV.uk

"Home Office Circular 018 / 2007 (Trespass on protected sites – sections 128–131 of the Serious Organised Crime and Police Act 2005)". www.GOV.uk. Government of the United Kingdom. 22 May 2007. Retrieved 18 July 2017.

Gensler.com

"Government Communication Headquarters (GCHQ)". www.Gensler.com. Gensler. Retrieved 17 December 2013.^{[permanent dead link‍]}

GloucesterCitizen.co.uk

"GCHQ plans shelved as new site for staff identified". www.GloucesterCitizen.co.uk. Gloucestershire Echo. 14 August 2011. Retrieved 11 July 2014.^{[permanent dead link‍]}

Telegraph.co.uk

Moore, Charles (11 October 2014). "GCHQ: 'This is not Blitz Britain. We sure as hell can't lick terrorism on our own'". www.Telegraph.co.uk. The Daily Telegraph. Retrieved 11 October 2014.
"Plans for new GCHQ go on view to public". www.Telegraph.co.uk. The Daily Telegraph.

TheGuardian.com

Norton-Taylor, Richard (10 June 2003). "The Doughnut, the less secretive weapon in the fight against international terrorism". The Guardian. Retrieved 15 December 2013.

TheTimes.co.uk

"GCHQ signals pride in its gay spooks". www.TheTimes.co.uk. The Times.

carillionplc.com

"GCHQ" (PDF). www.Carillionplc.com. Carillion plc. Archived from the original (PDF) on 27 April 2016. Retrieved 4 August 2014.

gchq.gov.uk

"Working environment". www.GCHQ.gov.uk. GCHQ. Archived from the original on 19 December 2013. Retrieved 17 December 2013.
"GCHQ showcases its volunteering and charity work at Community Day 2013". www.GCHQ.gov.uk. Cheltenham, Gloucestershire: GCHQ. 8 November 2013. Archived from the original on 19 December 2013. Retrieved 17 December 2013.

gloucestershireecho.co.uk

"GCHQ gets Royal visit at London office". www.GloucestershireEcho.co.uk. Gloucestershire Echo. 30 November 2013. Archived from the original on 24 September 2015. Retrieved 11 July 2014.
"Beautiful buildings to be nominated for awards". www.GloucestershireEcho.co.uk. Gloucestershire Echo. 13 October 2011. Archived from the original on 14 July 2014. Retrieved 11 July 2014.
"Prime Minister visited GCHQ in Cheltenham". www.GloucestershireEcho.co.uk. Gloucestershire Echo. 11 October 2008. Archived from the original on 24 September 2015. Retrieved 11 July 2014.
"GCHQ turns the Cheltenham 'doughnut' yellow to show support for Guide Dogs". www.GloucestershireEcho.co.uk. Gloucestershire Echo. 7 October 2015. Archived from the original on 11 October 2015. Retrieved 10 February 2016.
"GCHQ to be lit up like a rainbow for International Day Against Homophobia, Transphobia and Biphobia". www.GloucestershireEcho.co.uk. Gloucestershire Echo. 17 May 2015. Archived from the original on 22 December 2015. Retrieved 10 February 2016.

web.archive.org

"GCHQ gets Royal visit at London office". www.GloucestershireEcho.co.uk. Gloucestershire Echo. 30 November 2013. Archived from the original on 24 September 2015. Retrieved 11 July 2014.
"Working environment". www.GCHQ.gov.uk. GCHQ. Archived from the original on 19 December 2013. Retrieved 17 December 2013.
"GCHQ" (PDF). www.Carillionplc.com. Carillion plc. Archived from the original (PDF) on 27 April 2016. Retrieved 4 August 2014.
"Beautiful buildings to be nominated for awards". www.GloucestershireEcho.co.uk. Gloucestershire Echo. 13 October 2011. Archived from the original on 14 July 2014. Retrieved 11 July 2014.
"Prime Minister visited GCHQ in Cheltenham". www.GloucestershireEcho.co.uk. Gloucestershire Echo. 11 October 2008. Archived from the original on 24 September 2015. Retrieved 11 July 2014.
"GCHQ showcases its volunteering and charity work at Community Day 2013". www.GCHQ.gov.uk. Cheltenham, Gloucestershire: GCHQ. 8 November 2013. Archived from the original on 19 December 2013. Retrieved 17 December 2013.
"GCHQ turns the Cheltenham 'doughnut' yellow to show support for Guide Dogs". www.GloucestershireEcho.co.uk. Gloucestershire Echo. 7 October 2015. Archived from the original on 11 October 2015. Retrieved 10 February 2016.
"GCHQ to be lit up like a rainbow for International Day Against Homophobia, Transphobia and Biphobia". www.GloucestershireEcho.co.uk. Gloucestershire Echo. 17 May 2015. Archived from the original on 22 December 2015. Retrieved 10 February 2016.