@article{espinoza ortiz_egydio de carvalho_2001,  title={Energy spectrum and eigenfunctions through the Quantum Section Method},  volume={31},  ISSN={0103-9733},  url={https://doi.org/10.1590/S0103-97332001000400003},  DOI={10.1590/S0103-97332001000400003},  number={4},  journal={Brazilian Journal of Physics},  publisher={Sociedade Brasileira de Física},  author={Espinoza Ortiz, J.S. and Egydio de Carvalho, R.},  year={2001},  month={Dec},  pages={538–545} }