
http://www.economics-ejournal.org/economics/journalarticles/2017-4

https://www.global-counsel.co.uk/sites/default/files/analysis/insight/download/Hard%20and%20Soft%20Political%20Risk.pdf

https://www.aspistrategist.org.au/is-the-europen-union-too-big-for-further-enlargement/