Vuokko, Riikka, Kaija Saranto, and Sari Palojoki. “Features of COVID-19 Applications and Their Impact on Contact Tracing: Results of Preliminary Review”. Finnish Journal of eHealth and eWelfare 13, no. 4 (November 10, 2021): 347–359. Accessed November 22, 2024. https://journal.fi/finjehew/article/view/109253.