@article{arbieto_2010,  title={On persistently positively expansive maps},  volume={82},  ISSN={0001-3765},  url={https://doi.org/10.1590/S0001-37652010000200002},  DOI={10.1590/S0001-37652010000200002},  number={2},  journal={Anais da Academia Brasileira de Ciências},  publisher={Academia Brasileira de Ciências},  author={Arbieto, Alexander},  year={2010},  month={Jun},  pages={263–266} }