1. A. Bohr, B.R. Mottelson, Nuclear structure, vol. 1 (Benjamin, New York, 1969)
2. A. Bohr, B.R. Mottelson, Nuclear structure, vol. 2 (Benjamin, New York, 1975)
3. W. Nazarewicz, M.A. Riley, J.D. Garrett, Nucl. Phys. A. 512, 61 (1990)
4. G. Herzberg, Molecular spectra and molecular structure, vol. 2 (Van Nostrand, New York, 1945)
5. D.R. Bès, Nucl. Phys. 49, 544 (1963)