1. Standard for structure maintenance (in Japanese);Japanese National Railways,1974
2. Design and maintenance of cut slope (in Japanese);Okuzono,1983
3. A criterion on estimating a possibility of boulder-fall on of slope (in Japanese);Murakami,1990
4. Multivariate Statistics (a Practical Approach);Flury,1983
5. Applied multivariate analysis (in Japanese);Sugiyama,1986