1. J. C. Slater, Phys. Rev. 51, 846 (1937).PHRVAO0031-899X
2. M. M. Saffren and J. C. Slater, Phys. Rev. 92, 1126 (1953).PHRVAO0031-899X
3. J. C. Slater, in Handbhuch der Physik, S. Flügge, Ed. (Springer‐Verlag, Berlin, 1956), Vol. 19.
4. J. H. Wood, Phys. Rev. 126, 517 (1962).PHRVAO0031-899X
5. R. Keown, Phys. Rev. 150, 568 (1966).PHRVAO0031-899X