@misc{indiciae314a97ec8b92,
  title = {Threshold limit values: historical perspectives and current practice.},
  author = {G E Ziem and B I Castleman},
  year = {1989},
  doi = {10.1097/00043764-198911000-00014},
  url = {https://pubmed.ncbi.nlm.nih.gov/2681586/},
  note = {Source identifier: 2681586}
}