https://www.tagesschau.de/inland/deutschlandtrend/deutschlandtrend-3368.html
http://www.progressives-zentrum.org/wp-content/uploads/2018/03/The-Future-of-the-Visegrad-Group_2018_ebook.pdf
https://onlinelibrary.wiley.com/doi/epdf/10.1111/jcms.13411
https://www.politico.eu/article/markus-soders-crumbling-empire/