@article{viterbo_lemes_braga_2014,  title={Variable phase equation in quantum scattering},  volume={36},  ISSN={1806-1117},  url={https://doi.org/10.1590/S1806-11172014000100010},  DOI={10.1590/S1806-11172014000100010},  number={1},  journal={Revista Brasileira de Ensino de Física},  publisher={Sociedade Brasileira de Física - SBF},  author={Viterbo, Vitor D. and Lemes, Nelson H.T. and Braga, João P.},  year={2014},  month={Jan},  pages={1310} }