@misc{indiciae4b264535900d,
  title = {Problems with using observational databases to compare treatments.},
  author = {D P Byar},
  year = {1991},
  doi = {10.1002/sim.4780100417},
  url = {https://pubmed.ncbi.nlm.nih.gov/2057663/},
  note = {Source identifier: 2057663}
}