1. O. Fischer,Appl. Phys. 16, 1 (1978).
2. K. Yvon, inCurrent Topics in Materials Science, E. Kaldis, ed. (North-Holland, Amsterdam, 1979), Volume 3, Chapter 2.
3. J. D. Jorgensen and D. G. Hinks,Bull. Am. Phys. Soc. 28, 301 (1983).
4. J. D. Jorgensen and D. G. Hinks,Bull. Am. Phys. Soc. 29, 230 (1984).
5. K. Yvon,Solid State Commun. 25, 327 (1978).