"United States Census, 1920," index and images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M4MW-SCH : accessed 15 May 2015), Charles M Slagle, Inguadona, Cass, Minnesota, United States; citing sheet 8A, family 154, NARA microfilm publication T625 (Washington D.C.: National Archives and Records Administration, n.d.); FHL microfilm 1,820,824.
"United States Census, 1940," index and images, FamilySearch (https://familysearch.org/ark:/61903/1:1:KSKM-3ZD : accessed 15 May 2015), Charles Slagle, Inguadona Township, Cass, Minnesota, United States; citing enumeration district (ED) 11-25, sheet 2A, family 32, NARA digital publication T627 (Washington, D.C.: National Archives and Records Administration, 2012), roll 1912.