"United States Census, 1910," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MKB2-ZPT : 29 October 2015), Martin Ferwerda in household of John Ferwerda, Passaic Ward 4, Passaic, New Jersey, United States; citing enumeration district (ED) ED 84, sheet 2B, NARA microfilm publication T624 (Washington, D.C.: National Archives and Records Administration, n.d.); FHL microfilm 1,374,918.