Plöger, Oliver (1 July 2009). "Neue Strafe für Ursula Haverbeck-Wetzel" [New penalty for Ursula Haverbeck-Wetzel]. Mindener Tageblatt (in German). Minden. Archived from the original on 3 July 2009. Retrieved 2 August 2015.
Niedersächsische Verfassungsschutzbericht 2012 [Lower Saxony Protection of the Constitution Report 2012] (PDF) (in German), Hannover: Niedersächsische Ministerium für Inneres und Sport (Lower Saxony Ministry of Interior and Sport), 2012, pp. 87, 102, 105, 107, retrieved 1 August 2015
Plöger, Oliver (1 July 2009). "Neue Strafe für Ursula Haverbeck-Wetzel" [New penalty for Ursula Haverbeck-Wetzel]. Mindener Tageblatt (in German). Minden. Archived from the original on 3 July 2009. Retrieved 2 August 2015.