From 18 August 1942 Israël Heijmans taught at the secondary modern school or Jewish students (ULO) in Enschede. He later taught drawing (as well?) at the Joods Lyceum in Enschede.
T. Wiegman, Enschede 1940 – 1945 (Enschede 1985) (96-97)
Zie voor meer informatie over Israël Heijmans en zijn echtgenote Ilse Gumprich: Herbert Boucher, Miracle of Survival. A Holocaust Memoir (Judah L. Magnes Museum, Berkely, CA, 1997), pag. 160-171.
In addition, a Jokos file (number 60625) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.