"Eurocopter's X³ hybrid helicopter makes aviation history in achieving a speed milestone of 255 knots during level flight", Helicopters (press release), Airbus.
"Eurocopter's X³ hybrid helicopter makes aviation history in achieving a speed milestone of 255 knots during level flight"، Helicopters (press release)، Airbus  الوسيط |الناشر= تم تجاهله (مساعدة); الوسيط |العنوان= تم تجاهله (مساعدة).