@misc{indiciae1c08a5800157,
  title = {Contrast illusions in perspective.},
  author = {R L Gregory},
  year = {1971},
  doi = {10.1038/234157b0},
  url = {https://pubmed.ncbi.nlm.nih.gov/4942681/},
  note = {Source identifier: 4942681}
}