@misc{indiciae8236895a36e1,
  title = {Density patterns in two-dimensional hoppers.},
  author = {GH Risto and HJ Herrmann},
  year = {1994},
  doi = {10.1103/physreve.50.r5},
  url = {https://pubmed.ncbi.nlm.nih.gov/9962016/},
  note = {Source identifier: 9962016}
}