1. National Death Index User's Manual;Bilgrad,1990
2. History and Organization of the Vital Statistics System;Hetzel,1997
3. Obtaining State Death Certificates;U.S. Department of Health and Human Services,1992
4. Test of the National Death Index;Stampfer;Am J Epidemiol.,1984
5. Mortality ascertainment in the veteran population;Fisher;Am J Epidemiol.,1995