https://blogs.lse.ac.uk/europpblog/2023/10/09/europes-xhiro/
https://www.bloomberg.com/politics/articles/2017-04-11/brexit-means-scots-need-to-make-informed-choice-sturgeon-says
https://www.sachverstaendigenrat-wirtschaft.de/fileadmin/dateiablage/gutachten/jg201819/Chapter_1.pdf