@article{cundall1979,
  title={A discrete numerical model for granular assemblies},
  author={Peter Cundall and Otto D. L. Strack},
  year={1979},
  journal={Géotechnique},
  doi={10.1680/geot.1979.29.1.47},
  url={https://doi.org/10.1680/geot.1979.29.1.47}
}