1. Johns Hopkins Center for Systems Science and Engineering , COVID-19 dashboard. https://coronavirus.jhu.edu/map.html. Accessed 17 June 2020.
2. From big data to important information;Bar-Yam;Complexity,2016
3. N. M. Ferguson ., Impact of non-pharmaceutical interventions (NPIs) to reduce COVID-19 mortality and healthcare demand. Imperial College COVID-19 Response Team (2020).
4. Epidemics with two levels of mixing
5. Invasion Threshold in Heterogeneous Metapopulation Networks