TY  - RPRT
TI  - Evaluating PPO performance using prior expenditure data.
AU  - J Zwanziger
AU  - R R Auerbach
PY  - 1991
DO  - 10.1097/00005650-199102000-00006
UR  - https://pubmed.ncbi.nlm.nih.gov/1899711/
ID  - 1899711
ER  -