8Nam W J, Choi H C. High Strength Steel Wire Rod for Suspension Coil Spring. Wire J. Inter. , 1996, (5):94-97.
9S.T. Furr, Laboratory Studies of Low-Chromium and Chromium-free Steels for Suspension Coil Springs.Society of Automotive Engineers, Inc. 800479 (1980) : 1851-1861.
10Akio Yoneguchi, Jefferey Schaad, Yutaka Kurebayashi ,et al.. Development of High Strength Spring Steel and Its Application to Automotive Coil Spring. 2000 Society of Automotive Entrineers. Inc. :101-107.