"United States Census, 1940," index and images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/KWBF-X7J : accessed 02 Mar 2014), Louis C Tolsma, Ward 20, Chicago, Chicago City, Cook, Illinois, United States; citing enumeration district (ED) 103-1367, sheet 13A, family 273, NARA digital publication of T627, roll 962.