1. G. A. Roberts, J. C. Hamaker Jr., and A. R. Johnson:Tool Steels, 3rd ed., American Society for Metals, Metals Park, 1962.
2. P. Payson:The Metallurgy of Tool Steels, John Wiley and Sons, Inc., New York, 1962.
3. G. Hoyle:Met. Rev., 1964, vol. 9, pp. 49–91.
4. G. Hobson and D. S. Tyas:Metals Mater., 1968, vol. 2, pp. 144–55.
5. A. Füssl:J. Iron Steellnst, 1971, vol. 209, pp. 505–12.