Jonas de Vries was a son of Izak de Vries and Marianne van Colle. He married in Amsterdam on 21 September 1938 to Marie van Praag. City Archive of Amsterdam, archive card of Izak de Vries.
In addition, a Jokos file (number 52780) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.