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

https://publications.parliament.uk/pa/cm201719/cmselect/cmworpen/848/848.pdf

http://ukandeu.ac.uk/wp-content/uploads/2018/10/The-mechanics-of-a-further-referendum-on-Brexit-Constitution-Unit-Report-1.pdf