1. K. N. R. Taylor and M. I. Darby, Physics of Rare Earth Solids (Chapman and Hall, 1972).
2. D. L. Huber, J. Phys. Chem. Solids 32, 2145 (1971).
3. S. V. Maleev, J. Exp. Theor. Phys. 39, 889 (1974).
4. R. S. Gekht, Fiz. Met. Metalloved. 55, 225 (1983).
5. P. Burgardt and M. S. Seehra, Phys. Rev. B 16, 1802 (1977).