https://www.cesifo-group.de/DocDL/ifoDD_18-01_03-09_Ochsner.pdf
https://www.diepresse.com/5837400/fluchtiger-wirecard-manager-war-geheimer-fpo-informant
http://carnegieeurope.eu/strategiceurope/75351
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/761852/05_December-_EU_Exit_Attorney_General_s_legal_advice_to_Cabinet_on_the_Withdrawal_Agreement_and_the_Protocol_on_Ireland-Northern_Ireland.pdf