@misc{indiciae17e638253d06,
  title = {Threshold contrast as a function of target complexity.},
  author = {S K Guth and J F McNelis},
  year = {1969},
  doi = {10.1097/00006324-196907000-00002},
  url = {https://pubmed.ncbi.nlm.nih.gov/5255766/},
  note = {Source identifier: 5255766}
}