This article has quite a few sources: http://www.migrationpolicy.org/article/free-movement-europe-past-and-present http://www.migrationpolicy.org/article/free-m

This article has quite a few sources: http://www.migrationpolicy.org/article/free-movement-europe-past-and-present http://www.migrationpolicy.org/article/free-movement-europe-... And a more recent report: http://ec.europa.eu/social/BlobServlet?docId=11945&langId=en http://ec.europa.eu/social/BlobServlet?docId=11945&langId=en