50 years to orbit: Dream Chaser’s crazy Cold War backstory. Ars Technica, 7. September 2012, abgerufen am 25. Dezember 2018 (englisch): „In 2006, SpaceDev went on to execute a licensing agreement with NASA to use the HL-20's design for its new Dream Chaser suborbital spacecraft.“
aviationweek.com
archive.aviationweek.com
Craig Covault: Show Time, Commercial space lifting off, thanks to more business-like approaches. In: Aviation Week & Space Technology. Volume 161, Number 12, 27. September 2004, S.26–27 (englisch, hinter Anmeldeschranke: http://archive.aviationweek.com/issue/20040927/#!&pid=26 [abgerufen am 29. Dezember 2018]).