1. 1) Takeshita, K.: "A Study on the Inspection Method of Track Irregularities (in Japanese)," RTRI Report, Special No.25, pp.30-48, 1998.
2. 2) Takeshita, K.: "Track Irregularity Inspection Method by Commercial Railway Vehicle," QR of RTRI, Vol.38, No.1, pp.6-12, 1997.