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2. M. Harvey: inAdvances in Nuclear Physics, Vol.1, edited byM. Baranger andE. Vogt (New York, N. Y., 1968).
3. S. G. Nilsson:Dan. Math. Fys. Medd., No. 29 (1955).
4. M. Moshinsky:Group theory and the many-body problem, inPhysics of Many-Particles Systems, edited byE. Meron (New York, N. Y., 1965).
5. TheQ m andL q, defined above, are related to Elliott’s operators (2,5)Q m E andL q E byL q E =L q,Q m E =−√6Q m.