1. (1) http://www.nssmc.com/(accessed on 10th Sep. 2018).
2. (2) http://www.jfe-steel.co.jp/release/2018/02/180215.html (accessed on 10th Sep. 2018).
3. (3) http://www.nssmc.com/company/publications/monthly-nsc/pdf/2009_8-9_191_01_05.pdf (accessed on 13th Aug. 2018).
4. (4) http://www.asada-metal.co.jp/PDF/High_Strength_S_F_W.pdf (accessed on 13th Aug. 2018).
5. (5) 日本産業規格JIS G 3502ピアノ線材.