http://fedtrust.co.uk/brexitthe-conservative-centre-cannot-hold/
https://ec.europa.eu/commission/publications/terms-reference-article-50-treaty-european-union-negotiations_en
https://ec.europa.eu/commission/sites/beta-political/files/slides_on_uk_technical_note_on_temporary_customs_arrangements.pdf
http://www.epc.eu/documents/uploads/pub_7788_whatnowoptionsforbrexit.pdf?cmpid=BBBXT061617_BIZ&utm_medium=email&utm_source=newsletter&utm_term=170616&utm_campaign=brexit