1. C. Kittel, Introduction to Solid State Physics (Wiley, New York, 1976)
2. A.M. Tishin, in Handbook of Magnetic Materials, vol. 12, ed. by K.H.J. Buschow (Elsevier, Amsterdam, 1999)
3. see, e.g., A. Furrer, K.A. Müller, J. Mesot, Swiss Patent No. 693284 (May 2003); US Patent No. 6,558,434 B1 (May 2003)
4. T. Strässle, A. Furrer, Z. Hossain, C. Geibel, Phys. Rev. B 67, 054407 (2003)
5. S. Rosenkranz, M. Medarde, F. Fauth, J. Mesot, M. Zolliker, A. Furrer, U. Staub, P. Lacorre, R. Osborn, R.S. Eccleston, V. Trounov, Phys. Rev. B 60, 14857 (1999)