Abraham de Vries and Elisabeth de Vos married in 1915 in Amsterdam. Besides the here mentioned son Alfred they also had a daughter Juliette, who passed away three days after her birth.
Stadsarchief Amsterdam, archiefkaart Abraham de Vries
In addition, a Jokos file (number 51361) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.