Yu.S.Makushkin, Vl.G.Tyuterev,
       Perturbation Methods and Effective  Hamiltonians  in Molecular
       Spectroscopy, Novosibirsk, "Nauka", 1984, pp.1-239. [ in Russian]

B.I.Zhilinskii, V.I.Perevalov,  Vl.G.Tyuterev
        Method of Irreducible Tensorial Operators in the Theory of Molecular Spectra,
        Novosibirsk, "Nauka", 1987, pp.1-231. [ French translation available from LPUB,
        University of Dijon, France]

Vl.G.Tyuterev, The generating function approach to the formulation of the
        effective rotation Hamiltonian, J.Mol.Spectrosc., 1992, 151,p97-129