https://www.esri.ie/system/files/publications/RB202025.pdf
https://www.npr.org/sections/health-shots/2020/06/22/880803278/how-germany-staffed-up-contact-tracing-teams-to-contain-its-coronavirus-outbreak?t=1602767268883&?ncid=newsltukhpmgpols&t=1602840505295&t=1602841634862
http://invs.santepubliquefrance.fr/publications/etat_sante_2017/ESP2017_Synthese.pdf
https://pdf.sciencedirectassets.com/272083/1-s2.0-S1090951623X00030/1-s2.0-S1090951622001109/main.pdf