"United States Census, 1870," index and images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/MN9G-SZF : accessed 17 December 2014), Dirk Zwight, Wisconsin, United States; citing p. 26, family 197, NARA microfilm publication M593, National Archives and Records Administration, Washington D.C.; FHL microfilm 553,220.