
http://ec.europa.eu/anti-fraud/media-corner/news/31-05-2017/olaf-2016-leading-way-combatting-fraud-through-large-transnational_en

http://www.oecd-ilibrary.org/docserver/download/5jlv2jhfnt48-en.pdf?expires=1494939516&id=id&accname=guest&checksum=08592067325A17BFB82AC6F6E15110B2

https://www.bruegel.org/analysis/defending-europe-without-us-first-estimates-what-needed