"United States Census, 1880," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MW68-BB3 : 20 February 2021), John Donald in household of Samuel Donald, Millvale, Allegheny, Pennsylvania, United States; citing enumeration district ED 39, sheet 333C, NARA microfilm publication T9 (Washington, D.C.: National Archives and Records Administration, n.d.), FHL microfilm 1,255,088.
"Pennsylvania, County Marriages, 1885-1950," database with images, FamilySearch (https://www.familysearch.org/ark:/61903/1:1:VFWX-DB9 : 10 March 2021), John Donald and Elizabeth G. Pfitzenmeier, 27 Mar 1895; citing Marriage, Allegheny, Pennsylvania, United States, multiple County Clerks, Pennsylvania.
"United States Census, 1900," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M3MH-V31 : accessed 24 July 2021), John Donald, Millvale borough Ward 2, Allegheny, Pennsylvania, United States; citing enumeration district (ED) 451, sheet 16A, family 296, NARA microfilm publication T623 (Washington, D.C.: National Archives and Records Administration, 1972.); FHL microfilm 1,241,369.
"United States Census, 1910," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MGQ7-Y4V : accessed 24 July 2021), John Donald, Millvale Ward 3, Allegheny, Pennsylvania, United States; citing enumeration district (ED) ED 164, sheet 7B, family 160, NARA microfilm publication T624 (Washington D.C.: National Archives and Records Administration, 1982), roll 1296; FHL microfilm 1,375,309.
"United States Census, 1930," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:X765-JTD : accessed 24 July 2021), John Donald, Brooklyn (Districts 0751-1000), Kings, New York, United States; citing enumeration district (ED) ED 906, sheet 2B, line 75, family 30, NARA microfilm publication T626 (Washington D.C.: National Archives and Records Administration, 2002), roll 1491; FHL microfilm 2,341,226.
"United States Census, 1940," database with images, FamilySearch (https://www.familysearch.org/ark:/61903/1:1:KQ1J-95C : 7 January 2021), John Donald, Brooklyn, New York City, New York, United States; citing enumeration district (ED) 24-37A, sheet 5B, line 66, family 221, 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 2547.
"United States Social Security Death Index," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:JR3Y-BY4 : 7 January 2021), John Donald, Nov 1963; citing U.S. Social Security Administration, Death Master File, database (Alexandria, Virginia: National Technical Information Service, ongoing).
"Virginia, Death Certificates, 1912-1987," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:QVRH-6KCM : 16 August 2019), John Donald in entry for Adam Donald, 23 Dec 1979; from "Virginia, Marriage Records, 1700-1850," database and images, Ancestry (http://www.ancestry.com : 2012); citing Alexandria, , Virginia, United States, entry #, Virginia Department of Health, Richmond.