"New York, Passenger Arrival Lists (Ellis Island), 1892-1924," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:JJQ6-K2V : accessed 16 July 2015), Stientje de Vries, 01 Jul 1914; citing departure port Rotterdam, arrival port New York, ship name Potsdam, NARA microfilm publication T715 and M237 (Washington D.C.: National Archives and Records Administration, n.d.).