1. 1) J. Fehling and E. Scheil: Z. Metallk., 53 (1962), 593;
2. G. F. L. Powell and L. M. Hogan: J. Inst. Metals, 93 (1964–1965), 55.
3. 2) V. Kondic and D. Shutt: J. Inst. Metals, 78 (1950–1951), 105;
4. J. A. E. Bell and W. C. Weingard: J. Inst. Metals, 94 (1966), 226.
5. 3) R. Ichikawa and T. Ohashi: Light Metals, 16 (1966), 304.