1. (1) Stone, D.H., 8th International Wheelset Congress, Vol.2 (1985), p.V-4/1.
2. (2) Fox, M.P. and Hewitt, M.G., 4th International Wheelset Congress, Vol.2 (1972), p.67.
3. (3) Castagna, T. et al., 4th International Wheelset Congress, Vol.3 (1972), p.108.
4. (4) Hirooka, T. et al., 4th International Wheelset Congress, Vol.3 (1972), p.91.
5. (5) Kigawa, K. et al., 7th International Wheelset Congress, Vol.1 (1981), p.1.