Margaret Gustafson Dates: "United States Social Security Death Index," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:JB4T-VZ3 : accessed 6 December 2015), Margaret Gustafson, 02 Jun 2004; citing U.S. Social Security Administration, Death Master File, database (Alexandria, Virginia: National Technical Information Service, ongoing).