"Massachusetts Marriages, 1841-1915," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:N4D4-9DK : 10 March 2021), Harold Howard Howland and Etta Olzora Mason, 18 Oct 1911; citing Lowell, Lowell, Penobscot, Massachusetts, United States, State Archives, Boston; FHL microfilm 2,409,904.
"United States Social Security Death Index," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:V9BH-947 : 11 January 2021), Harold Howland, Jul 1976; citing U.S. Social Security Administration, Death Master File, database (Alexandria, Virginia: National Technical Information Service, ongoing).