@article{silveira_ziebell_schneider_gaelzer_2004,  title={The dispersion relation for electrostatic fluctuations in weakly inhomogeneous plasmas},  volume={34},  ISSN={0103-9733},  url={https://doi.org/10.1590/S0103-97332004000800024},  DOI={10.1590/S0103-97332004000800024},  number={4b},  journal={Brazilian Journal of Physics},  publisher={Sociedade Brasileira de Física},  author={Silveira, O. J. G. and Ziebell, L. F. and Schneider, R. S. and Gaelzer, R.},  year={2004},  month={Dec},  pages={1638–1644} }