https://theconversation.com/eu-citizens-proposal-a-lawyer-examines-the-detail-80111
http://carnegieeurope.eu/2017/06/15/bringing-brexit-back-to-reality-pub-71262
https://www.instituteforgovernment.org.uk/sites/default/files/publications/negotiating-brexit-preparing-talks-uk-future-relationship-eu-FINAL_1.pdf
http://uk.businessinsider.com/former-eu-negotiator-mays-government-has-handled-brexit-in-the-absolute-worst-way-2017-7