
https://blogs.lse.ac.uk/brexit/2020/02/21/migration-how-scotland-hoped-to-do-things-differently/

http://www.cesifo-group.de/ifoHome/publications/working-papers/CESifoWP/CESifoWPdetails?wp_num=6441&CESifoWP.search=+

https://facesofconflict.crisisgroup.org/atrapados-en-el-tapon-migrantes-y-traficantes-en-el-darien/?lang=es