@article{mcharris_2005,  title={Nonlinearities in quantum mechanics},  volume={35},  ISSN={0103-9733},  url={https://doi.org/10.1590/S0103-97332005000300003},  DOI={10.1590/S0103-97332005000300003},  number={2b},  journal={Brazilian Journal of Physics},  publisher={Sociedade Brasileira de Física},  author={McHarris, Wm. C.},  year={2005},  month={Jun},  pages={380–384} }