"Massachusetts Births, 1841-1915," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:FX6S-PX5 : 20 February 2021), Allen Ber Clark, 02 Mar 1887, Beverly, Essex, Massachusetts; citing reference ID #p225, 34, Massachusetts Archives, Boston; FHL microfilm 1,428,239.
"United States Census, 1900," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M95B-T4B : accessed 30 May 2021), Allen B Clarke in household of J Frank Clarke, Beverly city Ward 3, Essex, Massachusetts, United States; citing enumeration district (ED) 260, sheet 6B, family 148, NARA microfilm publication T623 (Washington, D.C.: National Archives and Records Administration, 1972.); FHL microfilm 1,240,640.
"Massachusetts, Town Clerk, Vital and Town Records, 1626-2001," database with images, FamilySearch (https://www.familysearch.org/ark:/61903/1:1:QPZR-QYLV : 19 April 2021), Alan Vere Clark and Mary Theresa McIntyre, 18 May 1909; citing Marriage, Ipswich, Essex, Massachusetts, United States, Massachusetts Secretary of the Commonwealth, Boston; FHL microfilm 007011628.
"United States Census, 1910," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M2J3-2QV : accessed 13 March 2023), Allan V Clark, Beverly Ward 3, Essex, Massachusetts, United States; citing enumeration district (ED) ED 271, sheet 3A, family 43, NARA microfilm publication T624 (Washington D.C.: National Archives and Records Administration, 1982), roll 581; FHL microfilm 1,374,594.