1. Steel Springs, Metals Handbook, tenth ed., vol. 1, ASM International, Materials Park, OH, 1990.
2. Manual on Design and Application of Helical and Spiral Springs, SAE HS-795, SAE International, Warrendale, PA, 1997.
3. ASM Handbook, Metal Progr., 1955, p. 81.
4. A.M. Wahl, Mechanical Springs, McGraw-Hill, New York, 1963.
5. Neutron diffraction methods for the study of residual stress fields