1. Bramm G, Novak P, Olsen DB (1981) A free-floating body as the rotor of a centrifugal blood pump for LVAD or TAH. Eur Soc Artif Organs Proc (Copenh) 8:41–45
2. Bramm G, Novak P, Olsen DB, Ruge I (1982) Axial centrifugal blood pump with magnetically suspended rotor life support systems. Proceedings, IX annual meeting of the ESAO, 1982. p 215–219
3. Bramm G, Novak P, Olsen DB, Ruge I (1982) A radial centrifugal blood pump with magnetically suspended rotor. 2nd int workshop. J Artif Organs 5(3): 161–163
4. Bramm G, Olsen DB, Novak P, Ruge I (1982) Seal- and bearingless blood pump conception for long term application to avoid coagulation and to reduce hemolysis. Proceedings, World congress on medical physics and biomedical engineering, pp 5, 25
5. Bramm G, Olsen DB, Novak P, Ruge I (1983) Ventil- und lagerfreie Blutpumpen zur Reduzierung von Blutschäden im Langzeiteinsatz. 17th Annual meeting at the German society of biomedical technology, Suppl 28:3