For citations:

Stepanenko D.A., Kindruk A.N. Variational Problem on Vibrations of Unequal-Thickness Rings and Its Application for Calculating Ultrasonic Vibration Concentrators. Science & Technique. 2024;23(4):295-303. (In Russ.) https://doi.org/10.21122/2227-1031-2024-23-4-295-303