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2. Anon. (2015) “Declassified Manned Orbiting Laboratory (MOL) Records”, National Reconnaissance Office, October 2015.
3. Anon. (2015) “Space Launch System at a Glance”, NP-2015-09-83-MSFC, Marshall Space Flight Center, NASA, September 2015.
4. Anon. (1967) “A Study of Advanced Airbreathing Launch Vehicles with Cruise Capability”, Lockheed Report IR 21042, Lockheed Aircraft Corporation, 1967.
5. Anon. (1966a) “Mission Requirements of Lifting Systems - Summary of Significant Results & Figures”, McDonnell Aircraft Report B947, McAIR, prepared under NASA NAS 9-3562 (declassified 1970).