1. A. V. Burenin,Usp. Fiz. Nauk.,163, No. 3, 87–96 (1993).
2. A. V. Burenin,Zh. Strukt. Khim.,35, No. 6, 31–34 (1994).
3. L. D. Landau and E. M. Lifshits,Quantum Mechanics [in Russian], Nauka, Moscow (1974).
4. I. G. Kaplan,Symmetry of Polyelectronic Systems [in Russian], Nauka, Moscow (1969).
5. M. D. Harmony, V. W. Laurie, R. L. Kuczkowski, et. at.,J. Phys. Chem. Ref. Data,8, No. 3, 619–721 (1979).