1. J.H. Van Vleck: Rev. Mod. Phys. 25, 220 (1953)
2. J.C. Slater: Phys. Rev. 49, 537, 931 (1936)
3. U.K. Poulson, J. Kollar, O.K. Andersen: J. Phys. F 6, L241 (1976)
4. V.L. Moruzzi, J.F. Janak, A.R. Williams: Calculated Electronic Properties of Metals (Pergamon, New York 1978)
5. J. Callaway: In Physics of Transition Metals, ed. by P. Rhodes, Conf. Series, No. 55 (Institute of Physics, Bristol 1981)