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
https://www.socialeurope.eu/2017/07/brexit-to-nowhere/
https://www.gov.uk/government/news/programme-for-fourth-round-of-uk-eu-article-50-negotiations