https://publications.parliament.uk/pa/cm201719/cmselect/cmcumeds/365/365.pdf
http://www.voxeurop.eu/en/2017/eu-uk-relations-5120821
https://ec.europa.eu/commission/publications/terms-reference-article-50-treaty-european-union-negotiations_en
https://exchange.cim.co.uk/editorial/is-brexit-marketers-biggest-challenge-no-the-apocalypse-is-coming/