1. 1) V.M.Segal, V.I.Reznikov, A.E.Drobyshevskiy and V.I.Kopylov: Russ. Metall., 1 (1981), 99.
2. 2) P.W.Bridgman: Studies in Large Plastic Flow and Fracture, McGraw-Hill, New York, NY, (1952).
3. 3) Y.Saito, N.Tsuji, H.Utsunomiya, T.Sakai and R.G.Hong: Scri. Mater., 39 (1998), 1221.
4. 4) R.Z.Valiev, Y.Estrin, Z.Horita, T.G.Langdon, M.J.Zehetbauer and Y.T.Zhu: JOM, 58, (2006), No. 4, 33.
5. 5) Y.Iwahashi, J.Wang, Z.Horita, M.Nemoto and T.G.Langdon: Scri. Mater., 35 (1996), 143.