"United States Census, 1900," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M9GY-NMF : 6 March 2015), Piebe A Krull, Clarksburg Township, Yolo, California, United States; citing sheet 1A, family 1, NARA microfilm publication T623 (Washington, D.C.: National Archives and Records Administration, n.d.); FHL microfilm 1,240,116.