@article{1225,
  author = {Shan Chang and Yong Qi and Hongzi ZHU and Jizhong Zhao and Xuemin Shen},
  title = {Footprint: Detecting sybil attacks in urban vehicular networks},
  year = {2012},
  journal = {IEEE Transactions on Parallel and Distributed Systems},
  volume = {23},
  number = {6},
  pages = {1103-1114},
  publisher = {IEEE},
}