Steele, Jeanette (17 November 2014). "Helicopter drone makes history". www.utsandiego.com. The San Diego Union-Tribune. Archived from the original on 30 March 2015. Retrieved 18 November 2014.
Steele, Jeanette (17 November 2014). "Helicopter drone makes history". www.utsandiego.com. The San Diego Union-Tribune. Archived from the original on 30 March 2015. Retrieved 18 November 2014.