@article{Zhang2008Multilevel,
  title={Multilevel Framework to Detect and Handle Vehicle Occlusion},
  author={Zhang, Wei and Wu, Q. M. J. and Yang, Xiaokang and Fang, Xiangzhong},
  journal={IEEE Transactions on Intelligent Transportation Systems},
  volume={9},
  number={1},
  pages={161-174},
  year={2008},
}