1. R. C. Hall, Metal Progr. 78 (August, 1956).
2. A. Taylor and R. M. Jones, Conference on Magnetism and Magnetic Materials (February, 1957), p. 246.
3. R. C. Hall (to be published).
4. D. Pavlovic and K. Foster (private communication, 1956).
5. M. Yamamoto and S. Taniguchi, Sci. Repts. Research Inst. Toho^ku Univ. 112 (1956).