Tham khảo Douglas_Y1B-7

Ghi chú
  1. ↑ Francillon 1979, các trang 139–140.
Tài liệu
  • Francillon, René J. McDonnell Douglas Aircraft since 1920. London: Putnam, 1979. ISBN 0-370-00050-1.
  • Pelletier, Alain J. "Bombers as Postmen: Boeing Y1O-35 and Y1B-7". Air Enthusiast, Volume 122, March / April 2006, các trang 30–40. ISSN 0143-5450.
  • Wagner, Ray. American Combat Planes. New York: Doubleday, 1982. ISBN 0-930083-17-2.