@article{helbing2002simulation,
  title={Simulation of pedestrian crowds in normal and evacuation situations},
  author={Helbing, Dirk and Farkas, Illes J and Molnar, Peter and Vicsek, Tam{\'a}s},
  journal={Pedestrian and evacuation dynamics},
  volume={21},
  pages={21--58},
  year={2002},
  publisher={Springer, Berlin}
}