1
Published: 2015;, [2015]
2
Published: 2010;, 2010.
3
Published: 2011;, 2011.
Superior document: Jahrbuch für direkte Demokratie
4
Published: 2012;, 2012.
Superior document: Jahrbuch für direkte Demokratie
5
Published: 2017;, 2017.
Superior document: Law & Literature, Volume 12
6
Published: 2019