1. 1. World Health Organization (WHO). Rubella. Available at <https://www.who.int/news-room/fact-sheets/detail/rubella>. Accessed Apr 27, 2023.
2. 2. National Institute of Infectious Diseases. (Japan): Rubella and congenital rubella syndrome. IASR (41). 2020. Available at <https://www.niid.go.jp/niid/ja/rubella-m-111/rubella-iasrtpc/9866-487t.html>. Accessed Apr 27, 2023. Japanese.
3. 3. National Institute of Infectious Diseases (Japan): Rubella Outbreak Trend Survey. Available at <https://www.niid.go.jp/niid/ja/hassei/3086-rubella-sokuhou-rireki.html>. Accessed Apr 27, 2023. Japanese.
4. 4. City of Yokohama: Yokohama City Outbreak Trends Survey of Infectious Diseases. Available at <https://www.city.yokohama.lg.jp/kurashi/kenko-iryo/eiken/kansen-center/kansensho/surveillance.html#zensu>. Accessed Apr 27, 2023. Japanese.
5. 5. Centers for Disease Control and Prevention (CDC). Rubella; 2021. In: Epidemiology and Prevention of Vaccine-Preventable Diseases. 2021. Available at <https://www.cdc.gov/vaccines/pubs/pinkbook/rubella.html>. Accessed Apr 27, 2023.