
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/650455/customs_bill_white_paper_print.pdf

http://blogs.lse.ac.uk/brexit/2018/09/25/brexit-has-become-unnegotiable-theresa-may-has-a-constitutional-duty-to-admit-that-truth/

https://blogs.sussex.ac.uk/uktpo/2018/02/15/sustainability-impact-assessment-for-post-brexit-britain/