1. W. Meyer, The Third International Congress of Quantum Chemistry, Kyoto, Japan, 1979; see Horizons Quantum Cehmistry, F. Fukui and B. Pullman, Eds. ( Reidel, Dordrecht, 1980 ), p. 3.
2. R. Ahlrichs, Compt. Phys. Commun. 17, 31 (1979).
3. A.C. Hurley, Electron Correlation in small Molecules ( Academic Press, New York, 1976 ).
4. W. Kutzelnigg, in Methods of Electronic Structure Theory, H.F. Schaefer, Ed. ( Plenum Press, New York, 1977 ), p. 129.
5. W. Meyer, Int. J. Quantum Chem. 5, 341 (1971)