Parental knowledge on the optional vaccines and the barriers in their use: A rural hospital-based study. Indian Journal of Child Health, [S. l.], v. 4, n. 1, p. 88–90, 2017. DOI: 10.32677/IJCH.2017.v04.i01.023. Disponível em: https://mansapublishers.com/index.php/ijch/article/view/181.. Acesso em: 18 apr. 2025.