@misc{indiciae7b052ea7e9fc,
  title = {PPD skin tests for workers.},
  author = {H J Silver},
  year = {1984},
  doi = {10.1017/s0195941700060112},
  url = {https://pubmed.ncbi.nlm.nih.gov/6563018/},
  note = {Source identifier: 6563018}
}