https://www.instituteforgovernment.org.uk/explainers/eu-withdrawal-bill-amendments-and-debates
http://ukandeu.ac.uk/brexit-a-french-perspective/
https://www.ft.com/content/ed91e91a-87f2-11e7-8bb1-5ba57d47eff7
https://www.nao.org.uk/wp-content/uploads/2018/10/The-UK-border-preparedness-for-EU-exit.pdf