http://www.odce.ie/Portals/0/Annual_Reports/ODCE_Annual_Report_2016_Full_Report.pdf
https://www.congress.gov/116/crpt/hrpt346/CRPT-116hrpt346.pdf
https://www.uokik.gov.pl/news.php?news_id=16818
https://www.cer.eu/sites/default/files/pbrief_corruption_27.4.21.pdf