@misc{indiciae7f86d1b32335,
  title = {Variation in proficiency testing performance by testing site.},
  author = {T M Stull and T L Hearn and J S Hancock and J H Handsfield and C L Collins},
  year = {1998},
  doi = {10.1001/jama.279.6.463},
  url = {https://pubmed.ncbi.nlm.nih.gov/9466641/},
  note = {Source identifier: 9466641}
}