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, vol. 11, no. 3, July 2023, pp. 653-9, doi:10.33394/j-ps.v11i3.8395.