http://www.cer.org.uk/sites/default/files/insight_JS_9.5.17.pdf
https://www.lobbycontrol.de/lobbyismus-in-der-eu/nach-katargate-fortschritte-und-blockaden-bei-neuen-regeln-fuer-eu-abgeordnete-111593/
https://www.smf.co.uk/wp-content/uploads/2024/04/Labour-Economics-April-2024.pdf
https://www.iod.com/Portals/0/PDFs/Campaigns%20and%20Reports/Europe%20and%20trade/IoD-Customising-Brexit.pdf?ver=2018-02-15-083137-800