1. Vibratsii v tekhnike: Spravochnik. T. 1. Kolebaniya lineinykh sistem (Vibrations in Engineering: a Handbook. Vol. 1. Vibrations in Linear Systems), Bolotin, V.V., Ed., Moscow: Mashinostroenie, 1978.
2. Russakovskii, E.M., Operator treatment of boundary problems with spectral parameters entering via polynomials in the boundary conditions, Funct. Anal. Appl., 1975, vol. 9, pp. 358–359.
3. Kapustin, N.Yu. and Moiseev, E.I., The basis property in $$L_p$$ of the systems of eigenfunctions corresponding to two problems with a spectral parameter in the boundary condition, Differ. Equations, 2000, vol. 36, no. 10, pp. 1498–1501.
4. Moiseev, E.I. and Kapustin, N.Yu., On the singularities of the root space of one spectral problem with a spectral parameter in the boundary condition, Dokl. Math., 2002, vol. 66, no. 1, pp. 14–18.
5. Kerimov, N.B. and Mirzoev, V.S., On the basis properties of one spectral problem with a spectral parameter in a boundary condition, Sib. Math. J., 2003, vol. 44, no. 5, pp. 813–816.