Marcus van Sijs and Vrouwtje Croese had eight children: Salomon (1906), Meijer (1908), Elkan (1910), Mozes (1912), Israel (1921) and three children who survived the war. One of the children lived somewhere else.
Addition of a visitor of the website
In addition, a Jokos file (number 21122) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.