@article{Bogdanov2019engineering,
author={Bogdanov, A.V. and Vasiltsov, V.V. and Golubenko, Y.V.},
title={Engineering computation of fiber laser focusing system},
journal={Science intensive technologies in mechanical engineering},
publisher={Bryansk State Technical University},
year={2019},
pages={21-24},
volume={2019},
issue={1},
}