"United States Census, 1940," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:K48W-DCB : 11 December 2019), Chester Allen in household of Otis Allen, Langley Township, Aiken, South Carolina, United States; citing enumeration district (ED) 2-22, sheet 2A, line 20, family 23, 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 3783.
Find A Grave, database and images (https://www.findagrave.com : accessed 03 February 2020), memorial page for O. Chester Allen (1928–1957), Find A Grave Memorial no. 30530521, citing Pine Grove Cemetery, Bath, Aiken County, South Carolina, USA ; Maintained by KarinH. (contributor 48065432).