World Health Organization. Vaccines and Immunization. Available from:
https://www.who.int/health-topics/vaccines-and-immunization
World Health Organization. Vaccines and Immunization: What is Vaccination? Available from:
https://www.who.int/news-room/questions-and-answers/item/vaccines-and-immunization-what-is-vaccination
World Health Organization. Essential Programme on Immunization. Available from:
https://www.who.int/teams/immunization-vaccines-and-biologicals/essential-programme-on-immunization
World Health Organization. Immunization Coverage. Available from:
https://www.who.int/news-room/fact-sheets/detail/immunization-coverage
World Health Organization. Measles. Available from:
https://www.who.int/teams/immunization-vaccines-and-biologicals/diseases/measles
Kementerian Kesehatan Republik Indonesia. Seputar Imunisasi. Available from:
https://ayosehat.kemkes.go.id/1000-hari-pertama-kehidupan/seputar-imunisasi
World Health Organization. A Brief History of Vaccination. Available from:
https://www.who.int/news-room/spotlight/history-of-vaccination/a-brief-history-of-vaccination