1. Wuenscher, H. F.: Manufacturing in Space. Astronautics and Aeronautics 10, No. 9 (1972) S. 42?54
2. Siekmann, J.; Eck, W.; Johann, W.: Experimentelle Untersuchungen über das Verhalten von Gasblasen in einem Null-g-Simulator. Z. Flugwiss. 22 (1974) S. 83?92
3. Wang, T. G.; Saffren, M. M.; Elleman, D. D.: Acoustical Levitation for Space Processing. Astronautics and Aeronautics 12, No. 7?8 (1974) S. 42?45
4. Harper, J. F.: The Motion of Bubbles and Drops Through Liquids. In: Advances in Applied Mechanics (Chia-shun Yih, ed.) 12, S. 59?129, New York, 1972
5. Clifton, J. V.; Hopkins, R. A.; Goodwin, D. W.: Motion of a Bubble in a Rotating Liquid. J. Spacecraft 6 (1969) S. 215?217