@misc{azad2017query,
  title={Query expansion techniques for information retrieval: A survey},
  author={Hiteshwar Kumar Azad and Akshay Deepak},
  year={2017},
  eprint={1708.00247},
  archivePrefix={arXiv},
  primaryClass={cs.IR},
  doi={10.1016/j.ipm.2019.05.009},
  url={https://arxiv.org/abs/1708.00247}
}