https://blogs.sussex.ac.uk/uktpo/2018/12/17/organising-the-second-referendum/
https://ukandeu.ac.uk/explainers/the-protocol-on-ireland-northern-ireland/?mc_cid=2bd4dc8e93&mc_eid=815b1928ec
http://www.cer.org.uk/sites/default/files/insight_js_st_9.6.17.pdf
https://www.instituteforgovernment.org.uk/sites/default/files/publications/negotiating-brexit-preparing-talks-uk-future-relationship-eu-FINAL_1.pdf