Columbia subject headings:
Blue Cross and Blue Shield Association.
Government employees' health insurance--Washington Metropolitan Area.
Group Health Association (Washington, D.C.)
Health surveys--Washington Metropolitan Area.
Hospital utilization--Washington Metropolitan Area.
Medical care--Washington Metropolitan Area.
Washington Metropolitan Area--Statistics, Medical.
Harvard subject headings:
Blue Cross and Blue Shield Association
Government employees' health insurance--Washington Metropolitan Area.
Group Health Association (Washington, D.C.)
Health surveys--Washington Metropolitan Area.
Hospital utilization--Washington Metropolitan Area.
Medical care--Washington Metropolitan Area.
Washington Metropolitan Area--Statistics, Medical.
Princeton subject headings:
Blue Cross and Blue Shield Association.
Government employees' health insurance--Washington Metropolitan Area.
Group Health Association (Washington, D.C.)
Health surveys--Washington Metropolitan Area.
Hospital utilization--Washington Metropolitan Area.
Medical care--Washington Metropolitan Area.
Washington Metropolitan Area--Statistics, Medical.