Agrawal, Satish Chandra, and Anita Kumari. “Immunization Status of Children and Its Decline With Age: A Hospital Based Study of 1000 Children at a Teaching Hospital in Western Uttar Pradesh”. Indian Journal of Community Health, vol. 26, no. 1, Mar. 2014, pp. 50-55, http://iapsmupuk.org/journal/index.php/IJCH/article/view/373.