Reference: 657 Title: Global Border Closures and Travel Restrictions During COVID-19 Summary: Governments worldwide imposed extensive travel restrictions during the COVID-19 pandemic, affecting 91% of the global population and disrupting economies. URL: https://www.pewresearch.org/short-reads/2020/04/01/more-than-nine-in-ten-people-worldwide-live-in-countries-with-travel-restrictions-amid-covid-19