@article{Guglielmi2021on,
author={Guglielmi, A.V. and Klain, B.I. and Potapov, A.S.},
title={On the group velocity of whistling atmospherics},
journal={Solnechno-Zemnaya Fizika},
publisher={INFRA-M Academic Publishing LLC.},
year={2021},
pages={70-74},
volume={7},
issue={4},
}