chapter 1 Statement of Eigenvalue Problems. Basic Methods of Their Solution -- chapter 2 The Method of Accelerated Convergence for the Sturm�Liouville Problem -- chapter 3 Approximate Analytical Solution of Perturbed Eigenvalue Problems -- chapter 4 Generalized Sturm�Liouville Problem -- chapter 5 Asymptotics of Eigenvalues and Eigenfunctions of the Generalized Sturm�Liouville Problem for Higher Vibration Modes -- chapter 6 Solutions of Fourth-Order Self-Conjugate Problems. Oscillation Properties -- chapter 7 The Method of Accelerated Convergence for Eigenvalue Problems for Fourth-Order Equations -- chapter 8 Perturbation Method in Eigenvalue Problems for Fourth-Order Equations -- chapter 9 Sturm�Liouville Problems for Vector-Valued Functions -- chapter 10 Vibrations and Stability of Elastic Systems -- chapter 11 Surface and Internal Waves in Heavy Ideal Fluid -- chapter 12 Parametric Vibrations of One-Dimensional Systems -- chapter 13 Vibrations of a Distributed Inhomogeneous System in a Rectangular Domain -- chapter 14 Free Vibrations of a Rectangular Membrane with Sharply Varying Surface Density -- chapter 15 Free Vibrations of Elastic Systems in Elliptic Domains.