http://www.europarl.europa.eu/cmsdata/115748/IPOL_IDA(2017)583130_EN.pdf
https://www.politico.eu/article/9-slippery-brexit-pledges/?utm_source=POLITICO.EU&utm_campaign=39a5c3d811-EMAIL_CAMPAIGN_2019_11_01_05_51&utm_medium=email&utm_term=0_10959edeb5-39a5c3d811-190380769
https://publications.parliament.uk/pa/ld201719/ldselect/ldeucom/63/63.pdf
https://www.gov.uk/government/news/david-davis-speech-to-the-suddeutsche-zeitung-economic-summit