1. Ruppe, H. O., Powersat. Acta Astronautica, 1988, 17, 1137–1138.
2. Ruppe, H. O., SPS revisited, Acta Astronautica, 1991, 25, 667.
3. Ruppe, H. O., Raumfahrt, ECON, Vol. 1. 1980, pp. 470–483.
4. Ruppe, H. O., Introduction to Astronautics, Vol. 2. Academic Press, New York, 1967.
5. Berger, B., High launch costs hinder development of space solar power. SpaceNews, September 18, 2000.