
https://www.bloomberg.com/news/articles/2019-09-11/world-s-oldest-customs-union-and-u-k-reach-a-post-brexit-deal

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

https://institute.global/sites/default/files/articles/Moving-On-How-the-British-Public-Views-Brexit-and-What-It-Wants-From-the-Future-Relationship-With-the-European-Union.pdf