
http://www.europarl.europa.eu/RegData/etudes/STUD/2017/602028/IPOL_STU(2017)602028_EN.pdf

https://ec.europa.eu/commission/commissioners/2014-2019/andriukaitis/blog/likening-eu-ussr-not-unreasonable_en

http://www.epc.eu/documents/uploads/pub_7576_northernirelandandbrexit.pdf