http://www.rug.nl/research/portal/files/41711829/cesifo1_wp6448.pdf
https://dbei.gov.ie/en/Publications/Publication-files/Ireland-and-the-Impacts-of-Brexit.pdf
http://www.euronews.com/2017/06/23/who-s-afraid-of-brexit?utm_source=newsletter&utm_medium=en&utm_content=who-s-afraid-of-brexit&_ope=eyJndWlkIjoiZjU3Y2JhYmUwMGUxZDFiNTUxOTU1ZDljNzExNTI1MmEifQ==
https://www.nao.org.uk/wp-content/uploads/2017/07/The-Customs-Declaration-Service.pdf