1. (1) Earnshaw, S., On the Nature of the Molecular Forces Which Regulate the Constitution of the Luminiferous Ether, Transactions Cambridge. Philosophical Society, Vol.7, Part I (1842), pp.97-112.
2. (2) The Magnetic Levitation Technical Committee of the Institute of Electrical Engineers of Japan, Magnetic Suspension Technology - Magnetic Levitation Systems and Magnetic Bearings -, (1993), Corona Publishing, Japan.
3. (3) The Japan Society of Mechanical Engineers, Basic and Application of Magnetic Bearings, (1995), Yokendo, Japan (in Japanese).
4. (4) Azuma, T., Kanemitsu, Y., Takahashi, N., Fukushima, Y., Matsushita, O., Magnetic Bearing Guidebook for Rotating Machine Designers, (2004), Japan Industrial Publishing, Japan (in Japanese), (2006), Toukashobo, Japan.
5. (5) Chiba, A., Fukao, T., Ichikawa, O., Oshima, M.,Takemono, M., Dorrell, D., Magnetic Bearings and Bearingless Drives, (2004), Newnes, Burlington.