@article{Agapov2019scientifically,
author={Agapov, S.I. and Sidyakin, Y.I. and Tolstyakov, A.F.},
title={Scientifically substantiated increase of piezoelectric transformer  reliability of cog-wheel ultrasonic machining},
journal={Science intensive technologies in mechanical engineering},
publisher={Bryansk State Technical University},
year={2019},
pages={17-22},
volume={2019},
issue={4},
}