@article{nivat1988,
  title={Fiftieth volume of theoretical computer science},
  author={Maurice Nivat},
  year={1988},
  journal={Theoretical Computer Science},
  doi={10.1016/0304-3975(88)90001-1},
  url={https://doi.org/10.1016/0304-3975(88)90001-1}
}