title: Alternative health care delivery systems: health maintenance organizations and preferred provider organizations.
authors.forename: D H
authors.initials: DH
authors.lastname: Cowan
mesh_terms: D006279:Health Maintenance Organizations / Q000331:legislation & jurisprudence* / Q000458:organization & administration; D007348:Insurance, Health / Q000331:legislation & jurisprudence*; D011243:Preferred Provider Organizations / Q000191:economics / Q000331:legislation & jurisprudence*; D014481:United States