@misc{indiciae86535f032497,
  title = {High-pass spatial frequency letters as clinical optotypes.},
  author = {B Howland and A Ginsburg and F Campbell},
  year = {1978},
  doi = {10.1016/0042-6989(78)90036-6},
  url = {https://pubmed.ncbi.nlm.nih.gov/706157/},
  note = {Source identifier: 706157}
}