1. Electron Spectroscopy for Chemical Analysis (ESCA);Siegbahn,1967
2. Narrow-Band Phenomena - Influence of Electrons with both Band and Localized Character;Fuggle,1988
3. See the series of stimulating articles in Physics Today, Vol. 44(1991) 22–74.
4. Moment Formation in Solids;Buyer,1984
5. See Ref. (2) for an historical survey of the development of these ideas.