1. Keja K, Chan C, Hayden G, Henderson RH. Expanded programme on immunization. World Health Stat Q 1988 Jan 1;41(2):59–63. Accessed 14 December 2023.
2. United Nations Children’s Fund. Immunization. 2023. https://www.unicef.org/immunization. Accessed 17 June 2023.
3. Immunization agenda 2030: a global strategy to leave no one behind. Geneva: World Health Organization; n.d. https://www.who.int/docs/default-source/immunization/strategy/ia2030/ia2030-document-en.pdf. Accessed 17 June 2030.
4. COVID-19 vaccine challenges: what have we learned so far and what remains to be done?;Forman;Health Pol,2021
5. Briss PA, Rodewald LE, Hinman AR, Shefer AM, Strikas RA, Bernier RR, et al. Task Force on Community Preventive Services. Reviews of evidence regarding interventions to improve vaccination coverage in children, adolescents, and adults. American journal of preventive medicine. 2000 Jan 1;18(1):97-140.