Thank you, Karen!

You are right: Those are my grandparents.

I know FamilySearch and also the Dutch archives. So there is no new information for me. Even if I follow all the links in there. For example: I only see a dead born child of her, but not my mother and not her sister (Else) and brother (Jan). I also don't find the date of her death and I don't remember when this was. It's quite long ago. Something 197x, if I remember right, but could also be 196x...

-> I have to continue my search in Poland, where my grandmothers family came from.

My Grandmother lived in Germany (Rotthausen, near Gelsenkirchen), before she married. I have a document from there, and it states, where her family came from. They came from Prussia (now Poland). I won't find anything more about them in Dutch archives. In my grandfather, who was from Rotterdam, I am not interested.

By the way: I have my family in MyHeritage. Here: https://www.myheritage.com/site-547158661/tschan

Best regards, Ze'ev
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[Ze'ev Itzhak Tschan, Har Adar, Israel]