@misc{indiciae6be24c55cedd,
  title = {Candidate reference method for determining serum theophylline applied to target-setting in external quality assessment and routine method evaluation.},
  author = {L M Thienpont and B Van Nieuwenhove and D Stöckl and A P De Leenheer},
  year = {1994},
  url = {https://pubmed.ncbi.nlm.nih.gov/7677808/},
  note = {Source identifier: 7677808}
}