http://www.express.co.uk/news/uk/840143/DNA-English-villages-foreigners-residents-study
https://theconversation.com/an-entry-fee-may-not-be-enough-to-save-venice-from-20-million-tourists-213703
https://op.europa.eu/en/publication-detail/-/publication/d73c833f-c34c-11eb-a925-01aa75ed71a1/language-en