1. World Health Organization. Operational considerations for COVID-19 surveillance using GISRS: interim guidance; 2020. Available from: https://apps.who.int/iris/handle/10665/331589. Accessed March 29, 2023.
2. European Centre for Disease Prevention and Control. Strategies for the surveillance of COVID-19. Available from: https://www.ecdc.europa.eu/en/publications-data/strategies-surveillance-covid-19. Accessed March 29, 2023.
3. European Centre for Disease Prevention and Control. COVID-19 surveillance guidance - Transition from COVID-19 emergency surveillance to routine surveillance of respiratory pathogens. Available from: https://www.ecdc.europa.eu/en/publications-data/covid-19-surveillance-guidance. Accessed March 29, 2023.
4. Establishing an ICD-10 code based SARI-surveillance in Germany – description of the system and first results from five recent influenza seasons
5. Robert-Koch-Institut. Wochenberichte zu COVID-19 (Weekly reports on COVID-19). Available from: https://www.rki.de/DE/Content/InfAZ/N/Neuartiges_Coronavirus/Situationsberichte/Wochenbericht/Wochenberichte_Tab.html;jsessionid=8286D2EA87630E86B19A3F1014BD10C8.internet051?nn=13490888. Accessed March 29, 2023.