https://ecfr.eu/wp-content/uploads/How-to-prevent-Germany-from-becoming-Eurosceptic.pdf
https://www.judiciary.senate.gov/imo/media/doc/Interim%20Staff%20Report%20FINAL.pdf
https://theconversation.com/an-entry-fee-may-not-be-enough-to-save-venice-from-20-million-tourists-213703