1. M. B. Maple, J. Wittig, and K. S. Kim,Phys. Rev. Lett. 23, 1375 (1969).
2. M. B. Maple, inMagnetism: A Treatise on Modern Theory and Materials, H. Suhl, ed. (Academic Press, New York, 1973), Chapter 10; and inProc. Conf. Superconductivity in d- and f-Band Metals, 1971, D. H. Douglass, ed. (AIP Conf. Proc. No. 4, Amer. Inst. Phys., New York, 1972), pp. 175?203.
3. E. Müller-Hartmann and J. Zittartz,Z. Phys. 234, 58 (1970).
4. W. Gey and E. Umlauf,Z. Phys. 242, 241 (1971).
5. M. B. Maple,Bull. Am. Phys. Soc. 18, 779 (1973).