Johnston, Jeff (July 2007). "Project Update"(PDF). Clipper Discovery Update: Underwater Admiralty Sciences Newsletter. pp. 1, 9. Archived from the original(PDF) on September 30, 2011. Retrieved September 16, 2009.
Johnston, Jeff (July 2007). "Project Update"(PDF). Clipper Discovery Update: Underwater Admiralty Sciences Newsletter. pp. 1, 9. Archived from the original(PDF) on September 30, 2011. Retrieved September 16, 2009.