Citation: Ay. Tsaune et Mp. Dyachenko, General scheme of splittings of degenerate eigensubspaces and eigenelements of self-adjoint operators in high orders of perturbation theory, J MATH PHYS, 41(8), 2000, pp. 5793-5813
Citation: Vn. Glushkov et Ay. Tsaune, Perturbation scheme for determining the electronic excitation energy of molecules with open shells, OPT SPECTRO, 87(2), 1999, pp. 249-254