1. Ya. M. Grigorenko, E. I. Bespalova, A. B. Kitaigorodskii, and A. I. Shinkar’, Free Vibrations of Elements of Shell Structures [in Russian], Naukova Dumka, Kyiv (1986).
2. P. A. Zhilin and T. P. Il’icheva, “Spectrum and vibration modes of a rectangular parallelepiped obtained using three-dimensional elasticity theory and plate theory,” Izv. AN SSSR, Mekh. Komp. Tel, No. 2, 94–103 (1980).
3. V. N. Moskalenko, “Natural vibrations of sandwich plates,” Izv. AN SSSR, Mekh. Mashinostr., No. 4, 125–130 (1962).
4. A. O. Rasskazov, I. I. Sokolovskaya, and N. A. Shul’ga, Theory and Design of Layered Orthotropic Plates and Shells [in Russian], Vyshcha Shkola, Kyiv (1986).
5. Z. Q. Cheng and R. C. Batra, “Exact correspondence between eigenvalues of membranes and functionally graded simply supported polygonal plates,” J. Sound Vibr., 229, No. 4, 879–895 (2000).