“…Such problems also arise in technical physics, mechanics, acoustics of flow channels, electrodynamics, and other areas [11], [36], [49]. In the case of separated boundary conditions, some variants of such problems are completely solved (see [5]- [7], [9], [10], [15]- [18], [22], [28], [42], [50]). Little studied are the boundary value problems in the case when the nonseparated boundary conditions depend on the spectral parameter.…”