"United States Census, 1920," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MW1F-KLN : accessed 2 July 2019), Marie Marshall in household of John Marshall, Duluth, St Louis, Minnesota, United States; citing ED 135, sheet 25A, line 15, family 483, NARA microfilm publication T625 (Washington D.C.: National Archives and Records Administration, 1992), roll 859; FHL microfilm 1,820,859.
"Minnesota Death Index, 1908-2002," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:V4CD-R5M : 4 December 2014), Mary C. Marshall, 17 Nov 1958; from "Minnesota Death Index, 1908-2002," database, Ancestry (http://www.ancestry.com : 2001); citing Saint Louis, Minnesota, record 1385212, certificate number 032185, Minnesota Department of Health, Minneapolis.