Ramayani O, Daulay R, Sofyani S, Lubis I. Factors related to missed opportunities for immunization at urban and suburban primary health centers in Medan. PI [Internet]. 28Feb.2007 [cited 22Nov.2024];47(1):21-. Available from: https://paediatricaindonesiana.org/index.php/paediatrica-indonesiana/article/view/337