
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/621848/60093_Cm9464_NSS_SDR_Web.pdf

https://researchbriefings.files.parliament.uk/documents/CBP-7212/CBP-7212.pdf

https://www.gov.uk/government/speeches/pm-commons-statement-on-eu-reform-and-referendum-22-february-2016