↑ "Vertical Takeoff & Landing Aircraft," John P. Campbell, The MacMillan Company, New York, 1962.
↑ "VTOL – Military Research Aircraft," Mike Rogers, Orion Books, New York, 1989.
↑ "Vertical Take-Off and Landing (VTOL) Aircraft," edited by I.B. Laskowitz, Annals of the New York Academy of Sciences, Vol 107, Art.1, March 25, 1963.
↑ "Straight Up - A History of Vertical Flight," Steve Markman and Bill Holder, Schiffer Publishing, 2000.
