1. A. Bohm, Y. Ne’eman, A. O. Barut and others, Dynamical groups and spectrum generating algebras, Volumes 1 and 2, World Scientific, Singapore, 1988.
2. A. Bohm and R. B. Teese, J. Math. Phys. 17 (1976), 94.
3. A. Arima and F. Iachello, Phys. Rev. Lett. 35(1975), 1069; for a rewiew see: F. Iachello and A. Arima, The Interacting Boson Model, Cambridge University Press, Cambridge, 1987.
4. F. Iachello, Chem. Phys. Lett. 78 (1981), 581; for a review see: F. Iachello and R. D. Levine, Algebraic Theory of Molecules, Oxford University Press, Oxford, 1993.
5. A. Frank and P. van Isacker, Algebraic Methods in Molecular & Nuclear Structure Physics, Wiley Interscience, 1994.