1. The Exploration Technology Development Program
2. 3NASASystemsEngineeringProcessesandRequirements,NPR7123.1B,April18,2013,pp.100-102.
3. 4NASASpaceFlightProgramandProjectManagementHandbookandtheStandingReviewBoardHandbook,NPR7120.5E, August 14, 2012.