1. A. N. Nikolaev, Trudy GPI im. Zhdanova,14, 2 (1958).
2. G. A. Vinogradov and Yu. N. Semenov, The Rolling of Metal Powders [in Russian], Moscow, Metallurgizdat (1960).
3. G. Naeser and F. Zirm, Stahl u. Eisen, Bd. 70, No. 22, pp. 995?1004 (1950).
4. P. Evans and G. Smith, Powder Metallurgy, No. 3, London, pp. 26?44 (1959).
5. A. P. Chekmarev and P. A. Klimenko, Nauch. Doklady Vysshei Shkoly, Metallurgiya, 1 (1958).