1. 1Joint Planning and Development Office 2004, Next Generation Air Transportation System Integrated Plan. http://www.jpdo.aero
2. FAA/Eurocontrol(2001)ActionPlan1FAA/EurcontrolCooperativeR&D,PrinciplesofOperationfortheUseofAirborne Separation Assurance Systems Version 7.1, 19June 2001
3. NASA, 1999, Concept Definition for Distributed Air/Ground Traffic Management (DAG-TM), http://www.asc.nasa.gov/aatt/dagconop.pdf