https://www.socialeurope.eu/refugees-how-could-we-possibly-get-here
https://www.migrationpolicy.org/article/spain-immigration-system-evolution?eType=EmailBlastContent&eId=a1fcdaaa-93ef-4a35-9397-e325534c6592&mc_cid=e4eef57c9d&mc_eid=d10a99d01e
https://wiiw.ac.at/the-labour-market-entry-and-integration-of-refugees-and-other-migrants-in-austria-dlp-6700.pdf
https://www.government.nl/documents/speeches/2018/09/24/speech-by-the-minister-of-foreign-affairs-stef-blok-to-kick-off-a-lunchtime-session-on-%E2%80%98action-against-human-trafficking-sanctions-accountability-and-the-rule-of-law%E2%80%99