1. Hagiwara, I., Tsuda, M. and Kitagawa, Y., Method of determining positions of beads, Japanese patent JP2727680B2 (1991).
2. Hagiwara, I., Tsuda, M., Kitagawa, Y. and Futamata, T., Method of determining positions of beads, United States Patent, Patent Number 5048345 (1991).
3. Hagiwara, I. and Nadayoshi, S., Folding process of cylindrical structures using origami model, International Journal of Automotive Engineering, Vol.34, No.4 (2003), pp.145-149 (in Japanese).
4. Hagiwara, I., Yamamoto, C., Tao, X. and Nojima, T., Optimization for crush characteristics of cylindrical origami structure using reversed spiral model, Transactions of the Japan Society of Mechanical Engineers, Series A, Vol.70, No.689 (2004), pp.36-42 (in Japanese).
5. Kitagawa, Y., Hagiwara, I. and Tsuda, M., Dynamic analysis of thin-walled columns with arbitrary section geometry subjected to axial crushing, Transactions of the Japan Society of Mechanical Engineers, Series A, Vol.57, No.537 (1991), pp.1135-1139 (in Japanese).