"United States Census, 1940," index and images, FamilySearch (https://familysearch.org/ark:/61903/1:1:KWBF-3QD : accessed 29 May 2015), John Hamstra, Ward 20, Chicago, Chicago City, Cook, Illinois, United States; citing enumeration district (ED) 103-1363, sheet 6A, family 128, NARA digital publication T627 (Washington, D.C.: National Archives and Records Administration, 2012), roll 962.