Batubara, Umar Said, and Muhammad Irwan Padli Nasution. “Immunization Servis Mobile Information System at Posyandu Medan Sunggal”. Prisma Sains : Jurnal Pengkajian Ilmu dan Pembelajaran Matematika dan IPA IKIP Mataram 11, no. 3 (July 3, 2023): 653–659. Accessed August 17, 2025. https://e-journal3.undikma.ac.id/index.php/prismasains/article/view/8395.