@misc{indiciaec609e8c9e18b,
  title = {Drug abuse proficiency testing.},
  author = {G O Guerrant and C T Hall},
  year = {1977},
  doi = {10.3109/15563657708987967},
  url = {https://pubmed.ncbi.nlm.nih.gov/852242/},
  note = {Source identifier: 852242}
}