"United States Census, 1930," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:XMDW-7LB : accessed 8 January 2022), Wilfred L Kimbal in household of Charles Kimbal, Enfield, Penobscot, Maine, United States; citing enumeration district (ED) ED 44, sheet 1B, line 55, family 13, NARA microfilm publication T626 (Washington D.C.: National Archives and Records Administration, 2002), roll 837; FHL microfilm 2,340,572.
"United States Census, 1940," database with images, FamilySearch (https://www.familysearch.org/ark:/61903/1:1:KMMP-3Z7 : 5 January 2021), Wilfred L Kimball in household of Charles E Kimball, Lincoln, Penobscot, Maine, United States; citing enumeration district (ED) 10-84, sheet 16A, line 22, family 317, Sixteenth Census of the United States, 1940, NARA digital publication T627. Records of the Bureau of the Census, 1790 - 2007, RG 29. Washington, D.C.: National Archives and Records Administration, 2012, roll 1487.
"United States Social Security Death Index," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:JBKR-22Z : 7 January 2021), Wilfred L Kimball, May 1988; citing U.S. Social Security Administration, Death Master File, database (Alexandria, Virginia: National Technical Information Service, ongoing).