1. Some methodological contributions to the Vickers microhardness technique;Zamfirova;Poly. Test.,2000
2. Improving precision of rubber test method;Spetz;Poly. Test.,1993
3. D. Tabor, Hardness of Metals, Clarendon Press, Oxford, 1951.
4. ISO 48, Physical testing of rubber, methods for the determination of hardness, 1994.
5. ISO 7619, Rubber—determination of indentation hardness by means of pocket hardness meters, 1997.