
https://ec.europa.eu/commission/publications/position-paper-essential-principles-citizens-rights_en

http://www.europarl.europa.eu/RegData/etudes/IDAN/2017/599352/EPRS_IDA%282017%29599352_EN.pdf

http://blogs.lse.ac.uk/brexit/2018/07/09/british-influence-in-brussels-had-been-far-greater-than-recognised/