
https://www.regjeringen.no/globalassets/upload/kilde/fkd/red/2004/0009/ddd/pdfv/228920-nilf_rapport_2004_9_s.pdf

https://yougov.co.uk/news/2017/04/26/voting-intention-conservatives-45-labour-29-25-26-/

https://www.parliament.uk/documents/commons-committees/culture-media-and-sport/Background%20paper%20-%202016%20Referendum%20Expenses%20Opinion%20-%20Matrix%20Chambers.pdf