http://www.europarl.europa.eu/RegData/etudes/STUD/2017/602028/IPOL_STU(2017)602028_EN.pdf
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/638135/6.3703_DEXEU_Northern_Ireland_and_Ireland_INTERACTIVE.pdf
https://www.publications.parliament.uk/pa/cm201617/cmselect/cmintrade/817/817.pdf
https://ukandeu.ac.uk/wp-content/uploads/2020/03/Parliament-and-Brexit-report.pdf