@inproceedings{vaswani2017,
  title={Attention is All You Need},
  author={Vaswani, Ashish and others},
  booktitle={NeurIPS},
  year={2017},
}

@article{orphan2019,
  title={A paper nobody cites},
  author={Ghost, A.},
  journal={Journal of Nothing},
  year={2019},
}

@article{duplicate_key,
  title={First definition},
  author={First, A.},
  year={2020},
}

@article{duplicate_key,
  title={Second definition of the same key},
  author={Second, B.},
  year={2021},
}