http://www.cer.eu/sites/default/files/pb_ireland_brexit_6.7.17.pdf
https://ukandeu.ac.uk/wp-content/uploads/2020/05/UKICE-Post-Brexit-Gov-NI-Report.pdf
https://ec.europa.eu/commission/sites/beta-political/files/slides_on_uk_technical_note_on_temporary_customs_arrangements.pdf
https://publications.parliament.uk/pa/ld201719/ldselect/ldeucom/15/15.pdf