1. 1) F. Rapatz: St. u. Ei., 61 (1941) 1073
2. 2) W.E. Ellis and M. Fleischmann: Trans. A.S.M., 46 (1954), 1039
3. 3) V.F. Zackay, J.F. Carlson, and P.L. Jackson: Trans. A.S.M., 48 (1956), 509
4. 4) G.F. Tisinai, J.K. Stanley, and C.H. Samans: Journal of Metals, 6 (1954), 1259
5. 5) Metallurgia. 54 (1956), No. 326, 290