@article{sessler_1999,  title={Bernhard Gross and the evolution of  modern electret research},  volume={29},  ISSN={0103-9733},  url={https://doi.org/10.1590/S0103-97331999000200003},  DOI={10.1590/S0103-97331999000200003},  number={2},  journal={Brazilian Journal of Physics},  publisher={Sociedade Brasileira de Física},  author={Sessler, G. M.},  year={1999},  month={Jun},  pages={220–225} }