HUBER, Mark. U.S. Selects Bell's V-280 Valor Tiltrotor For New Assault Aircraft [online]. ainonline, 2022-12-05 [cit. 2022-12-06]. Dostupné online. (anglicky)
Textron’s Bell V-280 Valor Chosen as New U.S. Army Long-Range Assault Aircraft [online]. businesswire, 2022-12-05 [cit. 2022-12-06]. Dostupné online. (anglicky)
PALEJA, Ameya. Sikorsky’s Defiant helicopter completes its flight of 700 nautical miles [online]. interestingengineering, 2022-04-01 [cit. 2022-08-22]. Dostupné v archivu pořízeném z originálu. (anglicky)
Good things come in threes: Boeing-Sikorsky to develop two larger X2 offshoots for JMR and Future Vertical Lift [online]. VerticalMag, 2014 [cit. 2022-03-23]. Dostupné online. (anglicky)
SB>1 DEFIANT Helicopter Completes Long-Endurance Flight to Nashville [online]. NASHVILLE: Lockheed Martin, 2022-03-31 [cit. 2022-08-22]. Dostupné v archivu pořízeném z originálu. (anglicky)
PALEJA, Ameya. Sikorsky’s Defiant helicopter completes its flight of 700 nautical miles [online]. interestingengineering, 2022-04-01 [cit. 2022-08-22]. Dostupné v archivu pořízeném z originálu. (anglicky)