https://www.esri.ie/system/files/publications/SUSTAT117.pdf
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/761852/05_December-_EU_Exit_Attorney_General_s_legal_advice_to_Cabinet_on_the_Withdrawal_Agreement_and_the_Protocol_on_Ireland-Northern_Ireland.pdf
http://www.ips-journal.eu/regions/europe/article/show/remainers-revenge-really-2101/
https://www.wto.org/english/res_e/booksp_e/blockchainrev18_e.pdf