↑ "United States, GenealogyBank Historical Newspaper Obituaries, 1815-2011", database, FamilySearch (https://familysearch.org/ark:/61903/1:1:Q53B-BTGB : 18 July 2020), Walter in entry for Michael Kostek, 1970.
↑ "United States, GenealogyBank Historical Newspaper Obituaries, 1815-2011", database, FamilySearch (https://familysearch.org/ark:/61903/1:1:Q53R-GQ15 : 18 July 2020), Marie Frances (Sojkowski) Kostek in entry for Walter Kostek, 1985.
↑ "United States Social Security Death Index," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:VMJW-H4F : 7 January 2021), Walter Kostek, Dec 1985; citing U.S. Social Security Administration, Death Master File, database (Alexandria, Virginia: National Technical Information Service, ongoing).
"United States Census, 1930," database with images, FamilySearch (https://www.familysearch.org/ark:/61903/1:1:XMP8-GD2 : accessed 19 July 2022), Walter Kostek in household of Michael Kostek, Enfield, Hartford, Connecticut, United States; citing enumeration district (ED) ED 130, sheet , line , family , NARA microfilm publication T626 (Washington D.C.: National Archives and Records Administration, 2002), roll ; FHL microfilm .
"United States Census, 1940," database with images, FamilySearch (https://www.familysearch.org/ark:/61903/1:1:K717-BQ7 : 8 January 2021), Walter Kosteh in household of Michael Kosteh, Enfield, Hartford, Connecticut, United States; citing enumeration district (ED) 2-66, sheet 6B, line 58, family 121, Sixteenth Census of the United States, 1940, NARA digital publication T627. Records of the Bureau of the Census, 1790 - 2007, RG 29. Washington, D.C.: National Archives and Records Administration, 2012, roll 503. Occupation: Tapestry weaver, rug factory