TY  - RPRT
TI  - Preferred provider organizations: performance, problems, and promise.
AU  - J Gabel
AU  - D Ermann
PY  - 1985
DO  - 10.1377/hlthaff.4.1.24
UR  - https://pubmed.ncbi.nlm.nih.gov/3997045/
ID  - 3997045
ER  -