
http://publications.iom.int/system/files/pdf/wmr_2018_en.pdf

http://blogs.lse.ac.uk/brexit/2017/06/05/uk-voters-including-leavers-care-more-about-reducing-non-eu-than-eu-migration/

https://ec.europa.eu/commission/sites/beta-political/files/citizens-rights-essential-principles-draft-position-paper_en.pdf