Liên quan North American P-51 Mustang North Carolina (lớp thiết giáp hạm) Northrop Grumman B-2 Spirit Northrop F-5 North American F-86 Sabre Northrop Grumman RQ-4 Global Hawk North American B-25 Mitchell North American F-100 Super Sabre Northrop P-61 Black Widow Northern Premier League 2014–15
Tài liệu tham khảo WikiPedia: North_American_XB-21 http://www.amazon.com/dp/B0007FFBSO http://www.joebaugher.com/usaf_bombers/b21.html http://www.nationalmuseum.af.mil/factsheets/factsh... http://www.aero-web.org/specs/northam/xb-21.htm http://www.aiaa-myaerospace.org/rhtp/stories/rusin... https://web.archive.org/web/20081121215312/http://... https://web.archive.org/web/20090114004727/http://... https://commons.wikimedia.org/wiki/Category:North_...
