@misc{indiciaea262a14ad1c6,
  title = {Geometry in visual space-some method-dependent (arti)facts.},
  author = {W H Ehrenstein},
  year = {1977},
  doi = {10.1068/p060657},
  url = {https://pubmed.ncbi.nlm.nih.gov/600665/},
  note = {Source identifier: 600665}
}