Dutch book named "Passage to freedom" : Jewish resistance in the Netherlands 1940-1945
On page 66:
In the technical service department worked also Fritz Klaber, a farmer
It almost failed. Stertzenbach and Fritz Klaber brought Bella, dressed in a work overall of the technical service department, through a gate at the side of the camp outside the barbed wire. Two boys of the Ordedienst (OD, illegal police force) of Westerbork,.......