Columbia subject headings:
Medical centers--United States--Statistics.
Sampling (Statistics)
Social surveys--United States.
Veterans' hospitals--United States--Statistics.
Veterans--Medical care--United States--Statistics.
Harvard subject headings:
Medical centers--United States--Statistics.
Sampling (Statistics)
Social surveys--United States.
Veterans' hospitals--United States--Statistics.
Veterans--Medical care--United States--Statistics.
Princeton subject headings:
Medical centers--United States--Statistics.
Sampling (Statistics)
Social surveys--United States.
Statistics.
Veterans' hospitals--United States--Statistics.
Veterans--Medical care--United States--Statistics.