@misc{indiciaeb03e0ed3b6e6,
  title = {Differences among color normals: classes I and II.},
  author = {W Richards},
  year = {1967},
  doi = {10.1364/josa.57.001047},
  url = {https://pubmed.ncbi.nlm.nih.gov/6035300/},
  note = {Source identifier: 6035300}
}