@misc{indiciae4065f98772f9,
  title = {Letter: Effect of directional-flow patterns upon motion thresholds.},
  author = {W Richards and J Dichgans},
  year = {1974},
  doi = {10.1364/josa.64.001148},
  url = {https://pubmed.ncbi.nlm.nih.gov/4852764/},
  note = {Source identifier: 4852764}
}