@article{krall1974,
  title={Principles of Plasma Physics},
  author={N. A. Krall and A. W. Trivelpiece and K. Symon},
  year={1974},
  journal={IEEE Transactions on Plasma Science},
  doi={10.1109/tps.1974.4316834},
  url={https://doi.org/10.1109/tps.1974.4316834}
}