Werner Warmbrunn, The Dutch under German Occupation, 1940—1945 (London, 1963), 24-25, 32-34, 261-265; Gerhard Hirschfeld, Nazi Rule and Dutch Collaboration: The Netherlands under German Occupation, 1940—1945 (Oxford, 1988 [1984]), 5-6. Konrad Kwiet, Reichskommissariat Niederlande: Versuch und Scheitern nationalsozialistischer Neuordnung (Stuttgart, 1968) argues that collaboration with the bourgeois establishment was less successful.