"United States Social Security Death Index," index, FamilySearch (https://familysearch.org/pal:/MM9.1.1/JPMP-QM5 (页面存档备份,存于互联网档案馆) : accessed 12 Feb 2013), Karen L Fonstad, 11 March 2005; citing U.S. Social Security Administration, Death Master File, database (Alexandria, Virginia: National Technical Information Service, ongoing).
"United States Social Security Death Index," index, FamilySearch (https://familysearch.org/pal:/MM9.1.1/JPMP-QM5 (页面存档备份,存于互联网档案馆) : accessed 12 Feb 2013), Karen L Fonstad, 11 March 2005; citing U.S. Social Security Administration, Death Master File, database (Alexandria, Virginia: National Technical Information Service, ongoing).