@INPROCEEDINGS{5767893,
  author={Peng, Yun and Choi, Byron and Xu, Jianliang},
  booktitle={2011 IEEE 27th International Conference on Data Engineering}, 
  title={Selectivity estimation of twig queries on cyclic graphs}, 
  year={2011},
  volume={},
  number={},
  pages={960-971},
  doi={10.1109/ICDE.2011.5767893}}