"Interview with Opposition Leader Gabriel 'We Have Much to Thank Grass For'". Interview with Konstantin von Hammerstein and Christoph Hickmann, www.spiegel.de. April 16, 2012.
"'Butting Heads with the Americans Doesn't Do Any Good'". Interview with Christian Schwärgerl and Markus Feldenkirchen, www.spiegel.de. January 29, 2008.