"United States Census, 1880," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M6P5-68P : 24 December 2015), Yke Krull, Merritt, Yolo, California, United States; citing enumeration district ED 158, sheet 304C, NARA microfilm publication T9 (Washington D.C.: National Archives and Records Administration, n.d.), roll 0086; FHL microfilm 1,254,086.