Jozeph had four siblings, who also have been killed during the Holocaust: William, Samson, Henriette and Alida. City Archive of Amsterdam, archive card of Mozes de Jong.
In addition, a Jokos file (number 25012) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.
Person is in the National Database of Victims of Persecution