According to a list with shops of Jewish owners, compiled by the Amsterdam police in 1940, Zacharias Swalef and his wife had a ladies' hats shop, address: Nieuwe Herengracht 197 in Amsterdam.
Abstracts of the police archives which are currently at the Amsterdam municipal archives
In addition, a Jokos file (number 15848) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.