Sutjipto A, Purba D, Nazir N, Purba MD, Siregar H. A survey on breastfeeding practices at Dr. Pirngadi Hospital Medan. PI [Internet]. 30Apr.1981 [cited 22May2024];21(3-4):51-0. Available from: https://paediatricaindonesiana.org/index.php/paediatrica-indonesiana/article/view/1179