"New Hampshire Marriages, 1720-1920," database, FamilySearch (https://familysearch.org/pal:/MM9.1.1/FDKS-3S6 : 10 February 2018), Willie Levasseur and Helene Perron, 30 Apr 1918; citing reference ; FHL microfilm 2,048,205.
"United States Census, 1920," database with images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/MH8V-9Y7 : accessed 12 March 2018), Helen Levasseur in household of William Levasseur, Manchester Ward 2, Hillsborough, New Hampshire, United States; citing ED 85, sheet 16A, line 46, family 398, NARA microfilm publication T625 (Washington D.C.: National Archives and Records Administration, 1992), roll 1010; FHL microfilm 1,821,010.