Check the information Open Archives has about Koopmans.
Check the Wie (onder)zoekt wie? register to see who is (re)searching Koopmans.
The Family tree Dijkstra publication was prepared by wijlen Jelke Dijkstra (as indicated in the digital, genealogical legacy, this publication remains online, contact is not possible).
When copying data from this family tree, please include a reference to the origin: wijlen Jelke Dijkstra, "Family tree Dijkstra", database, Genealogy Online (https://www.genealogieonline.nl/dijkstra-stamboom/I4094.php : accessed January 22, 2026), "Sijtske Rinses Koopmans".
Copy warning
Genealogical publications are copyright protected. Although data is often retrieved from public archives, the searching, interpreting, collecting, selecting and sorting of the data results in a unique product. Copyright protected work may not simply be copied or republished.
Please stick to the following rules
Request permission to copy data or at least inform the author, chances are that the author gives permission, often the contact also leads to more exchange of data.
Do not use this data until you have checked it, preferably at the source (the archives).
State from whom you have copied the data and ideally also his/her original source.