@misc{indiciae6b7d50a18d5e,
  title = {Vision testing beads.},
  author = {R Goodman},
  year = {1987},
  doi = {10.1136/adc.62.1.103},
  url = {https://pubmed.ncbi.nlm.nih.gov/3813631/},
  note = {Source identifier: 3813631}
}