The father of the Vischjager family was Fish dealer. The family lived in the Transvaalbuurt in Amsterdam. Among the seven children were two twins: Emanuel and Sophia, and Abram and Lena.
Amsterdam Municipal Archives; record card of Branca Mok
In addition, a Jokos file (number 50326) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.