Norris, Guy; Kelly, Emma (3 April 2001). "Boeing Sonic Cruiser Ousts 747X". Flight International. Archived from the original on 4 November 2019. Retrieved 4 November 2019.
Kingsley-Jones, Max; Norris, Guy (29 November 2005). "Enhanced A340 to take on 777". Flight International. Archived from the original on 7 March 2016. Retrieved 29 October 2017.
Norris, Guy; Kelly, Emma (3 April 2001). "Boeing Sonic Cruiser Ousts 747X". Flight International. Archived from the original on 4 November 2019. Retrieved 4 November 2019.
Kingsley-Jones, Max; Norris, Guy (29 November 2005). "Enhanced A340 to take on 777". Flight International. Archived from the original on 7 March 2016. Retrieved 29 October 2017.