1947, Great Britain. National Coal Board, A Selection of General Addresses Delivered Before the National Coal Board Summer School, Cambridge, 1947, page 10
2010 May 19, R. Moore, Nuclear Illusion, Nuclear Reality: Britain, the United States and Nuclear Weapons, 1958-64 (Nuclear Weapons and International Security since 1945), Springer, page 18
2015 April 19, Tony Blackman, Anthony Wright, Valiant Boys: True Stories from the Operators of the UK's First Four-Jet Bomber, Grub Street Publishing, page 51