Table of Contents

General ideas of the recursion operator method and adjoint representation.- Linear matrix bundle.- BC group and general integrable equations under reductions.- Quadratic bundle with Z 2 grading.- Polynomial and rational bundles.- Polynomial and rational bundles.- General differential spectral problem.- Generalization and reductions of the differential spectral problem and integrodifferential spectral problems.- Two-dimensional matrix spectral problem.- Two-dimensional differential spectral problem.- Towards to the general theory of recursion structure of nonlinear evolution equations.