Three telegrams remain of Aaltje Abas-de Vries concerning her transport to Westerbork. There are also several letters she wrote in Westerbork. Jewish Historical Museum Documents collection, inv.nr 4373
In addition, a Jokos file (number 11198) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.