1. M. P. Melkov, Hard Facing of Autotractor Parts [in Russian], Avtotransizdat, Moscow (1962).
2. E. G. Konovalov and V. A. Sidorenko, Rotational Finishing and Hardening Surface Treatments [in Russian], Vysshaya Shkola, Minsk (1962).
3. S. N. Aivazyan, Statistical Study of Relationships [in Russian], Metallurgiya, Moscow (1968).
4. V. K. Vigdorchik et al., Microhardness of Metals [in Russian], Metallurgizdat, Moscow (1963).