1. Orenstein WA, Perry RT, Halsey NA. The clinical significance of measles: A review. The Journal of Infectious Diseases. 2004;189(Suppl 1):S4-S16
2. Lahariya C. A brief history of vaccines & vaccination in India. Indian Journal of Medical Research. 2014;139:491-511
3. Hoshaw-Woodard S. Description and Comparison of the Methods of Cluster Sampling and Lot Quality Assurance Sampling to Assess Immunization Coverage. Geneva: Department of Vaccines and Biologicals, World Health Organization; 2001
4. Datta A, Mog C, Das S, Datta S. A cross-sectional study to assess the immunization coverage and vaccine dropout rates among 12 to 23 months old children in a rural area of Tripura. International Journal. 2017;6(2):394
5. Singh J, Jain DC, Sharma RS, Verghese T. Evaluation of immunization coverage by lot quality assurance sampling compared with 30-cluster sampling in a primary health Centre in India. Bulletin of the World Health Organization. 1996;74(3):269