@article{JS2009Xie_Clustering,
  title={Clustering-Based Approximate Scheme for Data Aggregation over Sensor Networks},
  author={Xie, Lei and Chen, Li Jun and Chen, Dao Xu and Xie, Li},
  journal={Journal of Software},
  volume={20},
  number={4},
  pages={1023--1037},
  year={2009},
}