1. A. P. Gulyaev and V. D. Zelenova, "Distribution of carbon in the carburized case on alloy steel", Metalloved. Term. Obrab. Met., No. 3, 14 (1960).
2. A. A. Popov, Theoretical Basis of Chemicothermal Treatment of Steel [in Russian], Metallurgizdat, Moscow (1962), p. 176.
3. T. A. Fridman, Machinist, No. 15, 538 (1951).
4. Trudy VNIIPT UGLEMASH;Z. M. Gamol'skaya,1966
5. L. S. Lyakhovich et al., Increasing the Service Life of Stamping Tools by Chemicothermal Treatment [in Russian], Minsk (1971), p. 21.