1. Health Care Financing Administration, ESRD Facility Survey File
2. US Renal Data System: 1993 Annual Report, chapter 2, 1993
3. Five year survival for end stage renal disease patients in the United States, Europe, and Japan, 1982-1987;Held;Am J Kidney Dis,1990
4. The urea reduction ratio (URR). A simple method for evaluating hemodialysis treatment;Lowrie,1991
5. The Basic Works of Aristotle,1941