
http://www.cesifo-group.de/ifoHome/publications/working-papers/CESifoWP/CESifoWPdetails?wp_num=6452&CESifoWP.search=+

https://www.opendemocracy.net/en/beyond-trafficking-and-slavery/exploitation-rule-not-exception/

https://theconversation.com/europeans-have-more-flexible-views-on-how-to-respond-to-irregular-migrants-than-policymakers-think-new-research-253473