1. Smith O. The 20 countries that have scrapped all mask rules. The Telegraph. 8 May 2022. https://www.telegraph.co.uk/travel/advice/mask-rules-covid-restrictions-plane-public-transport-travel-summer-2022/
2. Ledsom A . Europe Travel: No Masks Needed In These EU Countries. Forbes 26 Apr 2022. https://www.forbes.com/sites/alexledsom/2022/04/26/europe-travel-no-masks-needed-in-these-eu-countries/
3. A worldwide assessment of changes in adherence to COVID-19 protective behaviours and hypothesized pandemic fatigue
4. Achenbach J, Johnson CY. Omicron could have a silver lining by boosting immunity, some experts say. But don’t bet on it. Washington Post. 7 January 2022. https://www.washingtonpost.com/health/2022/01/07/omicron-silver-lining-boost-immunity/
5. Pandemic fatigue? How adherence to covid-19 regulations has been misrepresented and why it matters