1. For a review see: T. Moriva: Spin Fluctuations in Itinerant-Electron Magnetism, Springer Ser. Solid-State Sci., Vol. 56 (Springer, Berlin, Heidelberg 1985)
2. For a review see: P.W. Anderson: In Solid State Physics, 14, 99 (Academic, New York 1963)
3. See the following reviews: K. Yosida: In Progress in Low Temperature Physics
4, 265 (North-Holland, Amsterdam 1964);
4. R.J. Elliott: In Magnetism, 29, 385 (Academic, New York 1965)
5. H. Suhl (ed.): Magnetism, Vol. 5 (Academic, New York 1973)