@misc{indiciae8d2002289f29,
  title = {[A study on the decrease of potency of PPD solution. Experiments using 3 H-PPD].},
  author = {M Toyohara and M Orii},
  year = {1972},
  url = {https://pubmed.ncbi.nlm.nih.gov/5012048/},
  note = {Source identifier: 5012048}
}