In the Beeldbank (Image Bank) of the (Dutch) Nationaal Archief photo’s can be found of events from the period 1880 – 1990. Included are many photo’s of Kolffs.
In total the Beeldbank contains approx. 500.000 photo’s. Material comes from several collections that have been gathered by the Dutch National Archives over the years. This link leads to English language navigation pages of Nationaal Archief, Beeldbank.
|More at this site on the Nationaal Archief at Links: Research|