Izak de Lange was a son of Joël de Lange and Jutje Boomstra. He was married to the here mentioned Chawa Lunskij. Joèl de Lange was their son.
Addition of a visitor of the website
In addition, a Jokos file (number 31964) on this person is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.