"United States Census, 1880," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MZ9P-7GG : 26 August 2017), Wilhelm Zaun in household of Christian Zaun, Helena, Scott, Minnesota, United States; citing enumeration district ED 116, sheet 131D, NARA microfilm publication T9 (Washington D.C.: National Archives and Records Administration, n.d.), roll 0633; FHL microfilm 1,254,633.
"United States Census, 1900," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M93P-H3M : accessed 20 September 2017), William Zaun in household of Christina Zaun, Helena Township New Prague village (pt.) Ward 2, Scott, Minnesota, United States; citing enumeration district (ED) 173, sheet 19A, family 319, NARA microfilm publication T623 (Washington, D.C.: National Archives and Records Administration, 1972.); FHL microfilm 1,240,789.
"United States Census, 1910," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M2PN-SR6 : accessed 20 September 2017), William Zaun, Helena, Scott, Minnesota, United States; citing enumeration district (ED) ED 140, sheet 3B, family 55, NARA microfilm publication T624 (Washington D.C.: National Archives and Records Administration, 1982), roll 722; FHL microfilm 1,374,735.
"United States Census, 1930," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:X3DL-991 : accessed 20 September 2017), William C Zaun, Faxon, Sibley, Minnesota, United States; citing enumeration district (ED) ED 7, sheet 3B, line 86, family 60, NARA microfilm publication T626 (Washington D.C.: National Archives and Records Administration, 2002), roll 1130; FHL microfilm 2,340,865.