1. German Federal Ministry for Research and Technology (BMFT), Hypersonic Technology Programme, edited 1988, Bonn, Germany, layout by IAB GmbH, Ottobrunn, printed by Parat-Druck, Munich.
2. E. H. Hirschel, H. G. Hornung, J. Mertens, H. Oertel, W. Schmidt, Summary of the principal features and results of the BMFT study entitled Determining Key Technologies as Starting Points for German Industry in the Development of Future Supersonic Transport Aircraft with a View to Possible Hypersonic Aircraft Projects, final report of the Study Group on Aerothermodynamics, published as MBB/LKE122/HYPAC/R/1, 31.03.1987, BMFT Ref. No. LFF9694/8681 (MBB-UL/UT), LFF8682(Do).
3. Messerschmitt-Bölkow-Blohm (MBB), Sänger—An Advanced European Two- Stage Space Transport System, The Potential Future European Scenario, flyer printed and distributed in West Germany by MBB 2537, May 1988.
4. German Federal Ministry for Research and Technology (BMFT), Hypersonic Technology Programme, Interim Report Phase I, issued by BMFT Monitoring Group, IAB GmbH, Ottobrunn, Germany, February 1990.
5. P. Kania, The German Hypersonic Technology Program—Overview, Sixth International Aerospace Planes and Hypersonic Technologies Conference, AIAA-95-6005, April 3–7, 1995 Chattanooga, Tennessee.