
http://openeurope.org.uk/today/blog/will-brexit-ground-flights-europe/

https://ec.europa.eu/commission/sites/beta-political/files/revised_withdrawal_agreement_including_protocol_on_ireland_and_nothern_ireland.pdf

https://www.gov.uk/government/news/david-davis-teesport-speech-implementation-period-a-bridge-to-the-future-partnership-between-the-uk-eu