@misc{indiciaeac184ef8f28c,
  title = {Selection in a preferred provider organization enrollment.},
  author = {J E Billi and C G Wise and S I Sher and L Duran-Arenas and L Shapiro},
  year = {1993},
  url = {https://pubmed.ncbi.nlm.nih.gov/8270421/},
  note = {Source identifier: 8270421}
}