34L05 General spectral theory
34L10 Eigenfunction expansions, completeness of eigenfunctions
34L15 Estimation of eigenvalues, upper and lower bounds
34L16 Numerical approximation of eigenvalues and of other parts of the spectrum
34L20 Asymptotic distribution of eigenvalues, asymptotic theory of eigenfunctions
34L25 Scattering theory
34L30 Nonlinear ordinary differential operators
34L40 Particular operators (Dirac, one-dimensional Schrödinger, etc.)
34L99 None of the above, but in this section