
https://blogs.lse.ac.uk/brexit/2019/04/15/brexit-lessons-from-the-silesian-backstop-of-1919-25/

https://www.gov.uk/government/speeches/commonwealth-has-key-role-to-play-in-the-bright-future-for-britain-article-by-boris-johnson

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/680366/Technical_Note_-_International_Agreements_in_the_Implementation_Period_-_CLEAN.pdf