1. 1) I. Koike and K. Seike: Engineering Science Course 36 Industrial Design, (Kyoritsu Shuppan Co., Ltd, Japan, 1978) pp.36-40.
2. 2) Nikkei design, (Nikkei Business Publications. Inc., Japan, 5, 2003) 66-71.
3. 3) T. Suzuki: Annual Design Review of JSSD. 7-7 (2001) 24-29.
4. 4) Nikkei design, (Nikkei Business Publications. Inc., Japan, 4, 2001) pp.60-61.
5. 5) T. Ikeda, T. Terasawa, A. Maemura and T. Tamura: Design Review of JSSD. 6-6 (2000) 36-39.