"New York, State Census, 1855," index and images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/K63T-RLY : accessed 5 January 2015), Hylkje Postnia in household of John Vandervelen, E.D. 1, Lancaster, Erie, New York, United States; count clerk offices, New York; FHL microfilm 825,682.