https://share.trin.cam.ac.uk/sites/public/Comms/Rogers_brexit_as_revolution.pdf
http://visual.ons.gov.uk/trading-places-uk-goods-trade-with-eu-partners/
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
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/756374/14_November_Draft_Agreement_on_the_Withdrawal_of_the_United_Kingdom_of_Great_Britain_and_Northern_Ireland_from_the_European_Union.pdf