ダグラス ドルフィン
↑ Francillon 1988, p. 103.
↑ Francillon 1988, p. 102.
↑ Francillon 1988, p. 104.
↑ Francillon 1988, pp. 105–107.
↑ Bowers 1982, pp. 11–25.
↑ Bowers 1982, pp. 49-50.
↑ "Mayflower of the Air ready for President." Popular Science, May 1933, p. 713. Retrieved: March 5, 2012.