@article{becker2002,
  title={Estimation of Average Treatment Effects Based on Propensity Scores},
  author={Sascha O. Becker and Andrea Ichino},
  year={2002},
  journal={The Stata Journal Promoting communications on statistics and Stata},
  doi={10.1177/1536867x0200200403},
  url={https://doi.org/10.1177/1536867x0200200403}
}