https://www.lse.ac.uk/european-institute/Assets/Documents/LEQS-Discussion-Papers/LEQSPaper169.pdf
http://blogs.lse.ac.uk/brexit/2017/07/19/euroscepticism-has-taken-hold-across-the-eu-but-it-has-many-different-roots/
https://euagenda.eu/upload/publications/untitled-124549-ea.pdf
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/856998/2020-01-08_a_new_decade__a_new_approach.pdf