http://blogs.sussex.ac.uk/uktpo/files/2017/11/Briefing-Paper-11.pdf
https://ukandeu.ac.uk/wp-content/uploads/2019/12/Brexit-the-manifestos-uncovered.pdf
http://www.acea.be/uploads/publications/ACEA_position_paper-Brexit.pdf
http://ecdpm.org/wp-content/uploads/ETTG-Brief-Keijzer-Medinilla-November-2017.pdf