@misc{indiciae83d3b2804e1c,
  title = {Evaluating PPO performance using prior expenditure data.},
  author = {J Zwanziger and R R Auerbach},
  year = {1991},
  doi = {10.1097/00005650-199102000-00006},
  url = {https://pubmed.ncbi.nlm.nih.gov/1899711/},
  note = {Source identifier: 1899711}
}