Aviation Week and Space Technology. "Navy awards UCAS-D contract to NorthropGrumman X-47 team. [失效連結] "F/A-18F approaches carrier autonomously, will soon
(PDF)存档于2011-07-24). NorthropGrumman Delivers 37th Global Hawk to US Air Force (页面存档备份,存于互联网档案馆) - Deagel.com, January 7, 2013 NorthropGrumman Receives $114