TY  - RPRT
TI  - Threshold limit values: historical perspectives and current practice.
AU  - G E Ziem
AU  - B I Castleman
PY  - 1989
DO  - 10.1097/00043764-198911000-00014
UR  - https://pubmed.ncbi.nlm.nih.gov/2681586/
ID  - 2681586
ER  -