@article{song20166,
  title={6-DOF image localization from massive geo-tagged reference images},
  author={Song, Yafei and Chen, Xiaowu and Wang, Xiaogang and Zhang, Yu and Li, Jia},
  journal={IEEE Transactions on Multimedia},
  volume={18},
  number={8},
  pages={1542--1554},
  year={2016},
  publisher={IEEE}
}