@inproceedings{feng2014sampling,
  title={Sampling dilemma: towards effective data sampling for click prediction in sponsored search},
  author={Feng, Jun and Bian, Jiang and Wang, Taifeng and Chen, Wei and Zhu, Xiaoyan and Liu, Tie-Yan},
  booktitle={Proceedings of the 7th ACM international conference on Web search and data mining},
  pages={103--112},
  year={2014},
  organization={ACM}
}