1. S. Kokubo, Science Reports of the Tohuko Imperial University, Japan, 21 (1932), p.256.
2. G. Sines, R. Carlson: ASTM Bulletin, (1952), p.34.
3. P.A. Blain, Metal Progress, 71 (1957), p.99.
4. ISO 14577, Instrumented indentation testing, Beuth Verlag Berlin, (2002).
5. C. Heermant, D. Dengel, Materialprüfung, 38 (1996) 9, p.374.