@article{mendonça_zhou_2000,  title={Geodesics without conjugate points and curvatures at infinity},  volume={72},  ISSN={0001-3765},  url={https://doi.org/10.1590/S0001-37652000000200002},  DOI={10.1590/S0001-37652000000200002},  number={2},  journal={Anais da Academia Brasileira de Ciências},  publisher={Academia Brasileira de Ciências},  author={MENDONÇA, SÉRGIO and ZHOU, DETANG},  year={2000},  month={Jun},  pages={117–124} }