@misc{indiciaef75c52b5685d,
  title = {Surface waves in vertically vibrated granular materials.},
  author = {HK Pak and RP Behringer},
  year = {1993},
  doi = {10.1103/physrevlett.71.1832},
  url = {https://pubmed.ncbi.nlm.nih.gov/10054511/},
  note = {Source identifier: 10054511}
}