@article{sousa jr._2001,  title={Rigidity theorems of Clifford Torus},  volume={73},  ISSN={0001-3765},  url={https://doi.org/10.1590/S0001-37652001000300003},  DOI={10.1590/S0001-37652001000300003},  number={3},  journal={Anais da Academia Brasileira de Ciências},  publisher={Academia Brasileira de Ciências},  author={SOUSA JR., LUIZ A. M.},  year={2001},  month={Sep},  pages={327–332} }