↑ "United States Census, 1910," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MV2Q-7PF : accessed 25 January 2020), John Markham in household of Charles Markham, Oakland Ward 4, Alameda, California, United States; citing enumeration district (ED) ED 110, sheet 6B, family 122, NARA microfilm publication T624 (Washington D.C.: National Archives and Records Administration, 1982), roll 70; FHL microfilm 1,374,083.
↑ "United States Census, 1920," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MH39-W26 : accessed 25 January 2020), John Markham in household of Charles Markham, Oakland, Alameda, California, United States; citing ED 29, sheet 14B, line 89, family 372, NARA microfilm publication T625 (Washington D.C.: National Archives and Records Administration, 1992), roll 87; FHL microfilm 1,820,087.
↑ "United States Census, 1930," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:XC6Y-6NG : accessed 25 January 2020), John E Markham, San Francisco (Districts 1-250), San Francisco, California, United States; citing enumeration district (ED) ED 155, sheet 15B, line 94, family 406, NARA microfilm publication T626 (Washington D.C.: National Archives and Records Administration, 2002), roll 200; FHL microfilm 2,339,935.
↑ Find A Grave, database and images (https://www.findagrave.com : accessed 25 January 2020), memorial page for John E. Markham (1905–1986), Find A Grave: Memorial #166944338, citing Mountain View Cemetery, Oakland, Alameda County, California, USA ; Maintained by Dave Johnson (contributor 47872017).
"California, County Marriages, 1850-1952," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:K82R-LGH : 10 December 2017), John Edgar Markham and Elsa Alice Smet, 05 Sep 1925; citing San Joaquin, California, United States, county courthouses, California; FHL microfilm 1,841,870.
Ancestry.com, database with index images, "California, Marriage Index, 1949-1959," Abbeline G Pearce and John E Markham, 17 Feb 1952, Alameda, California, USA; California Department of Health and Welfare. California Vital Records—Vitalsearch (www.vitalsearch-worldwide.com). The Vitalsearch Company Worldwide, Inc., Pleasanton, California. Ancestry Record 5186 #20053673 with attached Image