"United States Census, 1910," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M5WS-HWW : accessed 3 January 2016), Marion Hopkinson in household of Norman Hopkinson, Warren, Herkimer, New York, United States; citing enumeration district (ED) ED 38, sheet 3B, NARA microfilm publication T624 (Washington, D.C.: National Archives and Records Administration, n.d.); FHL microfilm 1,374,965.
"United States Census, 1920," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MJLN-YSP : accessed 3 January 2016), Marian Hopkinson in household of Norma Hopkinson, Columbia, Herkimer, New York, United States; citing sheet 4A, NARA microfilm publication T625 (Washington D.C.: National Archives and Records Administration, n.d.); FHL microfilm 1,821,115.
"United States Census, 1930", database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:X7ZK-NCV : accessed 3 January 2016), Marian J Hopkinson in entry for Florence Hopkinson, 1930.