1. T. E. Norman, A. Solomon, and D. V. Doane:Trans. Am. Foundrymen’s Soc., 1959, vol. 67, pp. 242–56.
2. M. M. Kruschov:Proc. Conf. Lubrication and Wear, p. 665, Institution of Mechanical Engineers, London, 1957.
3. J. C. Hamaker and A. M. Bayer:Cobalt, 1968, no. 38, p. 3.
4. A. R. Rosenfield and A. J. McEvily: AGARD Rep. 1973, AGARD-R-610, pp. 24–54.
5. K. H. Zum Gahr:Arch. Eisenhuettenw., 1978, vol. 49, pp. 581–86.