Izaac Workum was a son of Meijer Workum and Esther Lessing. He married 5 August 1936 to Keetje Wijnschenk.
Izaac had three other siblings, who have been killed too during the Holocaust: David, Judith and Levie. One brother and his family have survived the war.
City Archive of Amsterdam, archive card…
In addition, a Jokos file (number 33378) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.