1. Coronavirus (Covid-19) cases. https://data.london.gov.uk/dataset/coronavirus-covid-19-cases
2. Covid-19: Data. https://www1.nyc.gov/site/doh/covid/covid-19-data.page
3. Infection scenarios for Russian cities. https://story.tutu.ru/scenarii-zarazhenija-gorodov-rossii/
4. The ins and outs of NYC commuting. https://www1.nyc.gov/assets/planning/download/pdf/planning-level/housing-economy/nyc-ins-and-out-of-commuting.pdf
5. London shapefile by ward. https://data.london.gov.uk/dataset/statistical-gis-boundary-files-london