@article{wang_farias_freire_1999,  title={Electric field effects on the confinement properties of GaN/Al x Ga1-xN zincblende and wurtzite nonabrupt quantum wells},  volume={29},  ISSN={0103-9733},  url={https://doi.org/10.1590/S0103-97331999000400010},  DOI={10.1590/S0103-97331999000400010},  number={4},  journal={Brazilian Journal of Physics},  publisher={Sociedade Brasileira de Física},  author={Wang, H. and Farias, G. A. and Freire, V. N.},  year={1999},  month={Dec},  pages={670–674} }