https://www.brookings.edu/wp-content/uploads/2018/03/fp_20180316_future_political_warfare.pdf
https://www.iedonline.eu/download/2017/IED-REPORT-Bratislava-2017.pdf
https://www.access-info.org/article/29101
http://blogs.lse.ac.uk/brexit/2018/11/23/hubert-butler-essay-prize-what-happened-to-europe-without-frontiers/