
https://publications.parliament.uk/pa/cm201719/cmselect/cmfaff/932/932.pdf

https://webunwto.s3.eu-west-1.amazonaws.com/s3fs-public/2020-07/200728-barometer-en.pdf

https://www.statnews.com/2021/03/04/the-short-term-middle-term-and-long-term-future-of-the-coronavirus/