1. 1) Usukouhan-Seikeigijyutsu-Kenkyuukai:Puresu-SeikeiNani-Handbook 3rd edition, (2007), 640-641, Nikkan- Kogyo-Shibun-Sha.
2. 2) Usukouhan-Seikeigijyutsu-Kenkyuukai:Puresu-SeikeiNani-Handbook 1st edition, (1987), 311-312, Nikkan- Kogyo-Shibun-Sha.
3. 3) Sakamoto, T., Ujihara, A. & Furubayashi, T.:J. Jpn. Soc. Technol. Plast., 38-337 (1989), 206-211.
4. 4) Yellup, J. M. & Painter, M. J:J. of Applied Metalworking, 4-1 (1985), 30-38.
5. 5) Sunaga, H. & Makinouchi, A.:J. Jpn. Soc. Technol. Plast., 39-444 (1998), 67-71.