@article{bialynicki-birula_2005,  title={On the linearity of the Schrödinger equation},  volume={35},  ISSN={0103-9733},  url={https://doi.org/10.1590/S0103-97332005000200003},  DOI={10.1590/S0103-97332005000200003},  number={2a},  journal={Brazilian Journal of Physics},  publisher={Sociedade Brasileira de Física},  author={Bialynicki-Birula, Iwo},  year={2005},  month={Jun},  pages={211–215} }